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Author SHA1 Message Date
Beman Dawes b48076cc36 Release 1.45.0
[SVN r66646]
2010-11-19 15:17:53 +00:00
Daniel James 7e74dc080e Merge documentation changes.
[SVN r64186]
2010-07-19 23:29:09 +00:00
Daniel James 3d44e92088 Merge documentation fixes.
* Use `doc/src/*.css` instead of `doc/html/*.css`.
* Remove wiki and people directories.
* Some documentation fixes.
* Left out `minimal.css` changes and boostbook changes because of clashes.


[SVN r63347]
2010-06-26 12:30:09 +00:00
Daniel James 947af90dbf Merge [57807]: rebuild numeric/conversion documentation.
[SVN r57809]
2009-11-20 10:05:09 +00:00
Troy D. Straszheim 0047a2d734 rm cmake from the release branch before it goes out broken. Policy dictates that you never commit to release, you commit to trunk and merge to release.
[SVN r56941]
2009-10-17 01:10:45 +00:00
Troy D. Straszheim 8a0a8727b9 Add basic copyright/license to keep cmake out of the inspection report
[SVN r55095]
2009-07-22 21:51:01 +00:00
John Maddock a05ae1dc97 Merge PDF build changes from Trunk.
[SVN r51417]
2009-02-23 18:39:32 +00:00
Troy D. Straszheim e0eee93fa5 merge of cmake build files from trunk per beman
[SVN r50756]
2009-01-24 18:57:20 +00:00
John Maddock 5963a9cb67 Merge fixes from Trunk.
Fixes #2392.

Change includes of <cmath> to <boost/config/no_tr1/config.hpp>.

Previously if Boost.TR1 was in the include path then including <cmath> pulls in all the new TR1 math functions, which in turn also requires linking to an external library. With auto-linking support this requires that library to have been built and be present in the library search path, even if the actual library under use is header only. 

[SVN r49314]
2008-10-13 09:00:03 +00:00
Daniel James 79760962d1 Rebuild the numeric/conversion and optional documentation. Which should fix a few links.
[SVN r49259]
2008-10-10 21:35:16 +00:00
Beman Dawes 225b672e44 Merge trunk
[SVN r47717]
2008-07-23 15:15:27 +00:00
Daniel James abb1d17829 Add minor documentation fixes to the release branch.
(I left out the changes to the hash library).

Merged via svnmerge from 
https://svn.boost.org/svn/boost/trunk

................
  r44807 | danieljames | 2008-04-27 08:39:49 +0100 (Sun, 27 Apr 2008) | 78 lines
  
  Merge in documentation fixes.  Apart from the change to optional's documenation
  Jamfile, which I included by mistake.
  
  I wrote about this at:
  
  http://lists.boost.org/Archives/boost/2008/04/136405.php
  
  Merged revisions 44585-44806 via svnmerge from 
  https://svn.boost.org/svn/boost/branches/doc
  
  ........
    r44585 | danieljames | 2008-04-19 16:25:27 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix broken link to vacpp in bjam docs.
  ........
    r44586 | danieljames | 2008-04-19 16:27:36 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix broken link to bcpp in bjam docs.
  ........
    r44587 | danieljames | 2008-04-19 16:33:58 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    DateTime documentation - Fix a link to the serialization library.
  ........
    r44588 | danieljames | 2008-04-19 16:35:36 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix some links in interprocess & intrusive.
  ........
    r44589 | danieljames | 2008-04-19 16:37:39 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix some links in the python docs.
  ........
    r44590 | danieljames | 2008-04-19 16:38:29 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Work around a quickbook bug which is affecting the python docs.
  ........
    r44591 | danieljames | 2008-04-19 16:39:34 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix a broken link in the numeric conversion docs.
  ........
    r44592 | danieljames | 2008-04-19 16:40:45 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix some links in the optional docs.
  ........
    r44593 | danieljames | 2008-04-19 16:42:09 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix link to the hash documentation from bimap.
  ........
    r44599 | danieljames | 2008-04-19 18:07:33 +0100 (Sat, 19 Apr 2008) | 2 lines
    
    Fix a typo in the format library.
  ........
    r44600 | danieljames | 2008-04-19 19:20:59 +0100 (Sat, 19 Apr 2008) | 1 line
    
    Initialise svnmerge.
  ........
    r44641 | danieljames | 2008-04-20 18:59:47 +0100 (Sun, 20 Apr 2008) | 2 lines
    
    Fix the lincense url in shared container iterator documentation.
  ........
    r44642 | danieljames | 2008-04-20 19:00:00 +0100 (Sun, 20 Apr 2008) | 2 lines
    
    Fix image link in the mpi documentation.
  ........
    r44643 | danieljames | 2008-04-20 19:00:11 +0100 (Sun, 20 Apr 2008) | 2 lines
    
    Fix a typo in the spirit docs.
  ........
    r44644 | danieljames | 2008-04-20 19:00:23 +0100 (Sun, 20 Apr 2008) | 2 lines
    
    Escape the slash so that quickbook doesn't think it the start of an italic section, and mess up the link. Refs #1844
  ........
    r44647 | danieljames | 2008-04-20 19:39:47 +0100 (Sun, 20 Apr 2008) | 2 lines
    
    Fix another typo in spirit docs.
  ........
................
  r45232 | danieljames | 2008-05-08 22:50:19 +0100 (Thu, 08 May 2008) | 1 line
  
  Fix some invalid xml by replacing ampersands with character entities.
................
  r45576 | danieljames | 2008-05-20 16:39:25 +0100 (Tue, 20 May 2008) | 20 lines
  
  Merge some small documentation fixes from the doc branch, and mark some
  previously merged changes as merged.
  
  Merged revisions 44811,45129,45142,45154,45281-45282,45365 via svnmerge from 
  https://svn.boost.org/svn/boost/branches/doc
  
  ........
    r45129 | danieljames | 2008-05-05 12:36:50 +0100 (Mon, 05 May 2008) | 2 lines
    
    Update navbar links in boostbook.
  ........
    r45282 | danieljames | 2008-05-11 14:15:31 +0100 (Sun, 11 May 2008) | 2 lines
    
    Group functions in the hash header - requires Frank's free-function-group fix.
    (not included in release branch).
  ........
    r45365 | danieljames | 2008-05-14 21:39:00 +0100 (Wed, 14 May 2008) | 2 lines
    
    Add boost.root to standalone hash documentation.
    (not included in release branch).
  ........
................


[SVN r45622]
2008-05-21 20:57:05 +00:00
Daniel James daadef8d1a Rebuild a lot of documentation.
[SVN r43650]
2008-03-16 11:38:32 +00:00
John Maddock ccffeecc40 Merged fixes for inspection report failures from the main Trunk.
[SVN r43616]
2008-03-15 09:36:05 +00:00
Matias Capeletto 7435918580 numeric/conversion docs new version
[SVN r43258]
2008-02-14 19:38:40 +00:00
Matias Capeletto 9487756e4b redirect to new conversion docs
[SVN r43252]
2008-02-14 18:09:34 +00:00
Matias Capeletto 35a5859da6 conversion docs fixes
[SVN r43251]
2008-02-14 18:08:16 +00:00
Beman Dawes 1ed1b2090e Full merge from trunk at revision 41356 of entire boost-root tree.
[SVN r41370]
2007-11-25 18:38:02 +00:00
Beman Dawes 5fb09c0c83 Starting point for releases
[SVN r39706]
2007-10-05 14:25:06 +00:00
nobody 0f0a2cecd4 This commit was manufactured by cvs2svn to create tag
'Version_1_34_1'.

[SVN r38286]
2007-07-24 19:28:14 +00:00
Fernando Cacciola b4dff23f4a none_t/none reimplemented to avoid precompiled header issues (thanks to Joe Gottam)
optional<T> now has direct relational operator
optional<T>::operator-> fixed for reference types


[SVN r37126]
2007-03-01 23:08:33 +00:00
Daniel James 8d28027378 Fix a broken link.
[SVN r36655]
2007-01-07 22:55:23 +00:00
Beman Dawes 864ea51c46 Merged copyright and license addition
[SVN r35907]
2006-11-07 19:27:00 +00:00
Rene Rivera f14990c43c Remove obsolete Boost.Build v1 files.
[SVN r35880]
2006-11-06 17:10:46 +00:00
Gennaro Prota a647a48fe5 fixed line-endings (Inspect tool)
[SVN r34781]
2006-07-29 20:42:19 +00:00
Nicola Musatti 4755739313 Updated Borland workaround
[SVN r33857]
2006-04-29 06:44:35 +00:00
nobody dd8e44c999 This commit was manufactured by cvs2svn to create branch 'RC_1_34_0'.
[SVN r33417]
2006-03-21 02:26:31 +00:00
61 changed files with 697 additions and 2870 deletions
+36
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@@ -0,0 +1,36 @@
# Boost.Numeric/Conversion
#
# Copyright (c) 2004-2007 Fernando Luis Cacciola Carballal
#
# Distributed under the Boost Software License, Version 1.0.
# (See accompanying file LICENSE_1_0.txt or copy at
# http://www.boost.org/LICENSE_1_0.txt)
# Quickbook
# -----------------------------------------------------------------------------
import quickbook ;
path-constant images : html ;
xml conversion
:
conversion.qbk
;
boostbook standalone
:
conversion
:
<xsl:param>boost.root=../../../../..
<xsl:param>html.stylesheet=boostbook.css
<xsl:param>toc.max.depth=2
<xsl:param>toc.section.depth=2
<xsl:param>chunk.section.depth=1
<format>pdf:<xsl:param>img.src.path=$(images)/
<format>pdf:<xsl:param>boost.url.prefix=http://www.boost.org/doc/libs/release/libs/numeric/conversion/doc/html
;
-109
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@@ -1,109 +0,0 @@
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<LINK REL="stylesheet" TYPE="text/css" HREF="../../../../boost.css">
<TITLE>Boost Numeric Conversion Library - Bounds</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
SUMMARY="header">
<TR>
<TH VALIGN="top" WIDTH="300">
<H3><A HREF="../../../../index.htm"><IMG HEIGHT="86" WIDTH="277"
ALT="C++ Boost" SRC="../../../../boost.png" BORDER="0"></A></H3> </TH>
<TH VALIGN="top">
<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1><A HREF="http://www.boost.org">Header </A><A
HREF="../../../../boost/numeric/conversion/bounds.hpp">boost/numeric/conversion/bounds.hpp</A></H1>
</TH>
</TR>
</TABLE><HR>
<H2>Contents</H2>
<UL>
<LI><A HREF="#introduction">Introduction</A></LI>
<LI><A HREF="#bounds"><code>template class bounds&ltN&gt</CODE></A></LI>
<LI><A HREF="#examples">Examples</A></LI>
<!--<LI><A HREF="#implementation">Implementation</A></LI>-->
<!--<LI><A HREF="#portability">Portability</A></LI>-->
</UL> <HR>
<H2><A NAME="introduction">Introduction</A></H2>
<P>To determine the ranges of numeric types with std:: numeric_limits
[18.2.1], different syntax have to be used depending on numeric type.
Specifically, numeric_limits&lt;T&gt;::min() for integral types returns the
minimum finite value, whereas for floating point types it returns the minimum
positive normalized value. The difference in semantics makes client code
unnecessarily complex and error prone. <BR> <BR>
boost::numeric::bounds&lt;&gt; provides a consistent interface for retrieving
the maximum finite value, the minimum finite value and the minimum positive
normalized value (0 for integral types) for numeric types. The selection of
implementation is performed at compile time, so there is no runtime overhead.
<BR>
<BR> </P> <HR>
<H2><A NAME="bounds"><CODE>traits class bounds&lt;N&gt;</CODE></A></H2>
<BLOCKQUOTE>
<PRE>template&lt;class N&gt;
struct bounds
{
static N lowest () { return <i>implementation_defined</i>; }
static N highest () { return <i>implementation_defined</i>; }
static N smallest() { return <i>implementation_defined</i>; }
};</PRE>
</BLOCKQUOTE>
<H3>Members</H3>
<PRE>lowest()</PRE>
<P>Returns the minimum finite value, equivalent to
numeric_limits&lt;T&gt;::min() when T is an integral type, and to
-numeric_limits&lt;T&gt;::max() when T is a floating point type. </P>
<PRE>highest()</PRE>
<P>Returns the maximum finite value, equivalent to
numeric_limits&lt;T&gt;::max(). </P>
<PRE>smallest()</PRE>
<P>Returns the smallest positive normalized value for floating point types with
denormalization, or returns 0 for integral types. <BR>
<BR>
</P> <HR>
<H2><A NAME="examples">Examples</A></H2>
<P>The following example demonstrates the use of numeric::bounds&lt;&gt; and the
equivalent code using numeric_limits: </P>
<BLOCKQUOTE>
<PRE>#include &lt;iostream&gt;
#include &lt;boost/numeric/conversion/bounds.hpp&gt;
#include &lt;boost/limits.hpp&gt;
int main() {
std::cout &lt;&lt; "numeric::bounds versus numeric_limits example.\n";
std::cout &lt;&lt; "The maximum value for float:\n";
std::cout &lt;&lt; boost::numeric::bounds&lt;float&gt;::highest() &lt;&lt; "\n";
std::cout &lt;&lt; std::numeric_limits&lt;float&gt;::max() &lt;&lt; "\n";
std::cout &lt;&lt; "The minimum value for float:\n";
std::cout &lt;&lt; boost::numeric::bounds&lt;float&gt;::lowest() &lt;&lt; "\n";
std::cout &lt;&lt; -std::numeric_limits&lt;float&gt;::max() &lt;&lt; "\n";
std::cout &lt;&lt; "The smallest positive value for float:\n";
std::cout &lt;&lt; boost::numeric::bounds&lt;float&gt;::smallest() &lt;&lt; "\n";
std::cout &lt;&lt; std::numeric_limits&lt;float&gt;::min() &lt;&lt; "\n";
return 0;
}</PRE>
</BLOCKQUOTE>
<hr>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 23 June 2004</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
-2
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@@ -8,8 +8,6 @@
http://www.boost.org/LICENSE_1_0.txt)
]
[#numeric_conversion_bounds]
[section bounds<> traits class]
[section Introduction]
+13 -13
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@@ -21,7 +21,7 @@ Distributed under the Boost Software License, Version 1.0.
[/ Cited Boost resources ]
[def __MPL_INTEGRAL_CONSTANT__ [@../../../../mpl/refmanual/integral-constant.html MPL's Integral Constant] ]
[def __MPL_INTEGRAL_CONSTANT__ [@../../../../mpl/doc/refmanual/integral-constant.html MPL's Integral Constant] ]
@@ -46,32 +46,32 @@ Distributed under the Boost Software License, Version 1.0.
The Boost Numeric Conversion library is a collection of tools to describe and
perform conversions between values of different
[link numeric_conversion_definitions_numeric_types numeric types].
[link boost_numericconversion.definitions.numeric_types numeric types].
The library includes a special alternative for a subset of `std::numeric_limits<>`,
the [link numeric_conversion_bounds bounds<>] traits class, which provides
a consistent way to obtain the [link numeric_conversion_definitions_range boundary]
values for the [link numeric_conversion_definitions_range range] of a numeric type.
the [link boost_numericconversion.bounds___traits_class bounds<>] traits class, which provides
a consistent way to obtain the [link boost_numericconversion.definitions.range_and_precision boundary]
values for the [link boost_numericconversion.definitions.range_and_precision range] of a numeric type.
It also includes a set of [link numeric_conversion_traits trait classes]
It also includes a set of [link boost_numericconversion.conversion_traits___traits_class trait classes]
which describes the compile-time
properties of a conversion from a source to a target numeric type.
Both [link numeric_conversion_cpp_arithmetic_types arithmetic] and
[link numeric_conversion_definitions_numeric_types user-defined numeric types] can be used.
Both [link boost_numericconversion.definitions.c___arithmetic_types arithmetic] and
[link boost_numericconversion.definitions.numeric_types user-defined numeric types] can be used.
A policy-based [link numeric_conversion_converter converter] object which
A policy-based [link boost_numericconversion.converter___function_object converter] object which
uses `conversion_traits` to select
an optimized implementation is supplied. Such implementation uses an optimal
range checking code suitable for the source/target combination.
* The converter's out-of-range behavior can be customized via an
[link numeric_conversion_policy_overflow_handler OverflowHandler] policy.
[link boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler OverflowHandler] policy.
* For floating-point to integral conversions, the rounding mode can be selected via the
[link numeric_conversion_policy_float_to_int_rounder Float2IntRounder] policy.
[link boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder Float2IntRounder] policy.
* A custom low-level conversion routine (for UDTs for instance) can be passed via a
[link numeric_conversion_policy_raw_converter RawConverter] policy.
[link boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter RawConverter] policy.
* The optimized automatic range-checking logic can be overridden via a
[link numeric_conversion_policy_user_range_checker UserRangeChecker] policy.
[link boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker UserRangeChecker] policy.
[endsect]
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<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<LINK REL="stylesheet" TYPE="text/css" HREF="../../../../boost.css">
<TITLE>Boost Numeric Conversion Library - Conversion Traits</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000ff" VLINK="#800080">
<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
SUMMARY="header">
<TR>
<TH VALIGN="top" WIDTH="300">
<H3><A HREF="../../../../index.htm"><IMG HEIGHT="86" WIDTH="277"
ALT="C++ Boost" SRC="../../../../boost.png" BORDER="0"></A></H3> </TH>
<TH VALIGN="top">
<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1><A HREF="http://www.boost.org">Header </A><A
HREF="../../../../boost/numeric/conversion/conversion_traits.hpp">boost/numeric/conversion/conversion_traits.hpp</A></H1>
</TH>
</TR>
</TABLE> <HR>
<H2>Contents</H2>
<DL CLASS="page-index">
<DT><A HREF="#types">Types</A></DT>
</DL>
<UL>
<LI><A HREF="#ncm"><CODE>enumeration boost::numeric::int_float_mixture_enum;</CODE></A></LI>
<LI><A HREF="#ncsm"><CODE>enumeration boost::numeric::sign_mixture_enum;</CODE></A></LI>
<LI><A HREF="#ncum"><CODE>enumeration boost::numeric::udt_builtin_mixture_enum;</CODE></A></LI>
<LI><A HREF="#ifm"><CODE>template class boost::numeric::int_float_mixture&lt;T,S&gt;</CODE></A></LI>
<LI><A HREF="#sm"><CODE>template class boost::numeric::sign_mixture&lt;T,S&gt;</CODE></A></LI>
<LI><A HREF="#ubm"><CODE>template class boost::numeric::udt_builtin_mixture&lt;T,S&gt;</CODE></A></LI>
<LI><A HREF="#isr"><CODE>template class boost::numeric::is_subranged&lt;T,S&gt;</CODE></A></LI>
<LI><A HREF="#nct"><CODE>template class boost::numeric::conversion_traits&lt;T,S&gt;</CODE></A></LI>
</UL>
<DL><DT><A HREF="#examples">Example(s)</A></DT></DL>
<HR>
<H2><A NAME="types"></A>Types</H2>
<H2><CODE><A NAME="ncm">enumeration int_float_mixture</A>_enum</CODE></H2>
<PRE>namespace boost { namespace numeric {
enum int_float_mixture_enum
{
integral_to_integral
,integral_to_float
,float_to_integral
,float_to_float
} ;
} } // namespace boost::numeric
</PRE>
<H2><CODE><A NAME="ncsm">enumeration sign_mixture</A>_enum</CODE></H2>
<PRE>namespace boost { namespace numeric {
enum sign_mixture_enum
{
unsigned_to_unsigned
,signed_to_signed
,signed_to_unsigned
,unsigned_to_signed
} ;
} } // namespace boost::numeric</PRE>
<H2><CODE><A NAME="ncum">enumeration udt_builtin_mixture</A>_enum</CODE></H2>
<PRE>namespace boost { namespace numeric {
enum udt_builtin_mixture_enum
{
builtin_to_builtin
,builtin_to_udt
,udt_to_builtin
,udt_to_udt
} ;
} } // namespace boost::numeric</PRE>
<hr>
<H2><A NAME="ifm"><CODE>template class int_float_mixture&lt;&gt;</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
template &lt;class T, class S&gt;
struct int_float_mixture : mpl::integral_c&lt;int_float_mixture_enum, <i>impl-def-value</i>&gt; {} ;
} } // namespace boost::numeric
</PRE>
<p>Classifying <code>S</code> and <code>T</code> as either <code>integral</code>
or <code>float</code>, this <a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constant</a>
indicates the combination of these attributes. <br>
Its <code>::value</code> is of enumeration type <A HREF="#ncm"><CODE>boost::numeric::int_float_mixture_enum</CODE></A>
</p>
<hr>
<H2><A NAME="sm"><CODE>template class sign_mixture&lt;&gt;</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
template &lt;class T, class S&gt;
struct sign_mixture : mpl::integral_c&lt;sign_mixture_enum, <i>impl-def-value</i>&gt; {} ;
} } // namespace boost::numeric
</PRE>
<p>Classifying <code>S</code> and <code>T</code> as either <code>signed</code>
or <code>unsigned</code>, this <a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constant</a>
indicates the combination of these attributes. <br>
Its <code>::value</code> is of enumeration type <A HREF="#ncm"><CODE>boost::numeric::sign_mixture_enum</CODE></A>
</p>
<hr>
<H2><A NAME="ubm"><CODE>template class udt_builtin_mixture&lt;&gt;</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
template &lt;class T, class S&gt;
struct udt_builtin_mixture : mpl::integral_c&lt;udt_builtin__mixture_enum, <i>impl-def-value</i>&gt; {} ;
} } // namespace boost::numeric
</PRE>
<p>Classifying <code>S</code> and <code>T</code> as either <code>user-defined</code>
or <code>builtin</code>, this <a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constant</a>
indicates the combination of these attributes. <br>
Its <code>::value</code> is of enumeration type <A HREF="#ncm"><CODE>boost::numeric::udt_builtin_mixture_enum</CODE></A>
</p>
<hr>
<H2><A NAME="isr"><CODE>template class is_subranged&lt;&gt;</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
template &lt;class T, class S&gt;
struct is_subranged : mpl::bool_&lt;<i>impl-def-value</i>&gt; {} ;
} } // namespace boost::numeric
</PRE>
<p>Indicates if the range of the target type T is a subset of the range of the source type S.
That is: if there are some source values which fall out of the Target type's range.<br>
It is a boolean <a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constant</a>..<br>
It does not indicate if
a <i>particular</i> conversion is effectively out of range; it indicates that
some conversion <i>might be</i> out of range because not all the source values
are representable as Target type.</p>
<hr>
<H2><A NAME="nct"><CODE>template class conversion_traits&lt;&gt;</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
template &lt;class T, class S&gt;
struct conversion_traits
{
mpl::integral_c&lt;int_float_mixture_enum , ...&gt; int_float_mixture ;
mpl::integral_c&lt;sign_mixture_enum , ...&gt; sign_mixture;
mpl::integral_c&lt;udt_builtin_mixture_enum, ...&gt; udt_builtin_mixture ;
mpl::bool_&lt;...&gt; subranged ;
mpl::bool_&lt;...&gt; trivial ;
typedef T target_type ;
typedef S source_type ;
typedef ... argument_type ;
typedef ... result_type ;
typedef ... supertype ;
typedef ... subtype ;
} ;
} } // namespace numeric, namespace boost
</PRE>
<BLOCKQUOTE>
<P>This traits class indicates some properties of a <i>numeric conversion direction</i>:
from a source type <code>S</code> to a target type <code>T</code>. It does not indicate the properties of
a <i>specific</i> conversion, but of the conversion <i>direction</i>. See
<A href="definitions.html#subranged">Definitions</A> for details.<br>
</P>
<P>The traits class provides the following
<a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constants</a>
of enumeration type. They express the <i>combination</i> of certain attributes of the Source and
Target types (thus they are call <i>mixture</i>):</P>
<TABLE BORDER="1">
<TR>
<TD>&nbsp;<CODE><B>int_float_mixture</B></CODE>&nbsp;</TD>
<TD>
<P>Same as given by the traits class <A HREF="#ifm"><CODE>int_float_mixture</CODE></A></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>sign_mixture</B></CODE>&nbsp;</TD>
<TD>
<P>Same as given by the traits class <A HREF="#sm"><CODE>sign_mixture</CODE></A></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>udt_builtin_mixture</B></CODE>&nbsp;</TD>
<TD>
<P>Same as given by the traits class <A HREF="#ubm"><CODE>udt_builtin_mixture</CODE></A></P>
</TD>
</TR>
</TABLE>
<P>The traits class provides the following
<a href="../../../mpl/doc/refmanual/integral-constant.html">MPL's Integral Constants</a>
of boolean type which indicates indirectly the relation between the Source and Target
<i>ranges</i>
(see <A href="definitions.html#range">Definitions</A> for details).</P>
<TABLE BORDER="1">
<TR>
<TD>&nbsp;<CODE> <B>subranged</B></CODE>&nbsp;</TD>
<TD>
<P>Same as given by <A HREF="#isr"><CODE>is_subranged</CODE></A></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE> <B>trivial</B></CODE>&nbsp;</TD>
<TD>
<P>Indicates if both Source and Target, <u>without cv-qualifications</u>, are
the same type.<br>
Its <code>::value</code> is of boolean type.</P>
</TD>
</TR>
</TABLE>
<P>The traits class provides the following types. They are the Source and Target
types classified and qualified for different purposes.</P>
<TABLE BORDER="1" width="720">
<TR>
<TD>&nbsp;<CODE><B>target_type</B></CODE>&nbsp;</TD>
<TD>
<P>The template parameter <CODE>T</CODE><EM> without cv-qualifications</EM></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>source_type</B></CODE>&nbsp;</TD>
<TD>
<P>The template parameter <CODE>S</CODE><EM> without cv-qualifications</EM></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>argument_type</B></CODE>&nbsp;</TD>
<TD>
<P>This type is either <CODE>source_type</CODE> or <CODE>source_type
const&amp;</CODE>. <BR> It represents the <I>optimal</I> argument type for the
<A HREF="converter.html">converter</A> member functions.<BR>
If <CODE>S</CODE> is a built-in type, this is <CODE>source_type</CODE>,
otherwise, this is <CODE>source_type const&amp;</CODE>. </P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>result_type</B></CODE></TD>
<TD>
<P>This type is either <CODE>target_type</CODE> or <CODE>target_type
const&amp;</CODE> <BR> It represents the return type of the
<A HREF="converter.html">converter</A> member functions.<BR>
If <CODE>T==S</CODE>, it is <CODE>target_type const&amp;</CODE>, otherwise,
it is <CODE>target_type</CODE>.</P>
</TD>
</TR>
<TR>
<TD height="37">&nbsp;<CODE><B>supertype</B></CODE></TD>
<TD height="37">
<P>If the conversion is <CODE>subranged</CODE>, it is <CODE>source_type</CODE>,
otherwise, it is <CODE>target_type</CODE></P>
</TD>
</TR>
<TR>
<TD>&nbsp;<CODE><B>subtype</B></CODE></TD>
<TD height="37">
<P>If the conversion is <CODE>subranged</CODE>, it is <CODE>target_type</CODE>,
otherwise, it is <CODE>source_type</CODE></P>
</TD>
</TR>
</TABLE> </BLOCKQUOTE> <HR>
<H2><A NAME="examples">Examples</A></H2>
<BLOCKQUOTE>
<PRE>#include &lt;cassert&gt;
#include &lt;typeinfo&gt;
#include &lt;boost/numeric/conversion/conversion_traits.hpp&gt;
int main()
{
// A trivial conversion.
typedef boost::numeric::conversion_traits&lt;short,short&gt; Short2Short_Traits ;
assert ( Short2Short_Traits::trivial::value ) ;
// A subranged conversion.
typedef boost::numeric::conversion_traits&lt;double,unsigned int&gt; UInt2Double_Traits ;
assert ( UInt2Double_Traits::int_float_mixture::value == boost::numeric::integral_to_float ) ;
assert ( UInt2Double_Traits::sign_mixture::value == boost::numeric::unsigned_to_signed ) ;
assert ( !UInt2Double_Traits::subranged::value ) ;
assert ( typeid(UInt2Double_Traits::supertype) == typeid(double) ) ;
assert ( typeid(UInt2Double_Traits::subtype) == typeid(unsigned int) ) ;
// A doubly subranged conversion.
assert ( (boost::numeric::conversion_traits&lt;short, unsigned short&gt;::subranged::value) );
assert ( (boost::numeric::conversion_traits&lt;unsigned short, short&gt;::subranged::value) );
return 0;
}
</PRE>
</BLOCKQUOTE>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 16 May 2005</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
+11 -27
View File
@@ -8,14 +8,10 @@
http://www.boost.org/LICENSE_1_0.txt)
]
[#numeric_conversion_traits]
[section conversion_traits<> traits class]
[section Types]
[#numeric_conversion_traits_int_float_mixture_enum]
[section enumeration int_float_mixture_enum]
namespace boost { namespace numeric {
@@ -32,8 +28,6 @@
[endsect]
[#numeric_conversion_traits_sign_mixture_enum]
[section enumeration sign_mixture_enum]
namespace boost { namespace numeric {
@@ -50,8 +44,6 @@
[endsect]
[#numeric_conversion_traits_udt_builtin_mixture_enum]
[section enumeration udt_builtin_mixture_enum]
namespace boost { namespace numeric {
@@ -68,8 +60,6 @@
[endsect]
[#numeric_conversion_traits_class_int_float_mixture]
[section template class int_float_mixture<>]
namespace boost { namespace numeric {
@@ -83,12 +73,10 @@ Classifying `S` and `T` as either integral or float, this __MPL_INTEGRAL_CONSTAN
indicates the combination of these attributes.
Its `::value` is of enumeration type
[link numeric_conversion_traits_int_float_mixture_enum `boost::numeric::int_float_mixture_enum`]
[link boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum `boost::numeric::int_float_mixture_enum`]
[endsect]
[#numeric_conversion_traits_class_sign_mixture]
[section template class sign_mixture<>]
namespace boost { namespace numeric {
@@ -102,12 +90,10 @@ Classifying `S` and `T` as either signed or unsigned, this __MPL_INTEGRAL_CONSTA
indicates the combination of these attributes.
Its `::value` is of enumeration type
[link numeric_conversion_traits_sign_mixture_enum `boost::numeric::sign_mixture_enum`]
[link boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum `boost::numeric::sign_mixture_enum`]
[endsect]
[#numeric_conversion_traits_class_udt_builtin_mixture]
[section template class udt_builtin_mixture<>]
namespace boost { namespace numeric {
@@ -121,12 +107,10 @@ Classifying `S` and `T` as either user-defined or builtin, this __MPL_INTEGRAL_C
indicates the combination of these attributes.
Its `::value` is of enumeration type
[link numeric_conversion_traits_udt_builtin_mixture_enum `boost::numeric::udt_builtin_mixture_enum`]
[link boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum `boost::numeric::udt_builtin_mixture_enum`]
[endsect]
[#numeric_conversion_traits_is_subranged]
[section template class is_subranged<>]
namespace boost { namespace numeric {
@@ -176,7 +160,7 @@ source values are representable as Target type.
This traits class indicates some properties of a ['numeric conversion] direction:
from a source type `S` to a target type `T`. It does not indicate the properties
of a ['specific] conversion, but of the conversion direction. See
[link numeric_conversion_definitions_subranged Definitions] for details.
[link boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype Definitions] for details.
The traits class provides the following __MPL_INTEGRAL_CONSTANT__\s of enumeration
type. They express the combination of certain attributes of the Source and
@@ -186,26 +170,26 @@ Target types (thus they are call mixture):
[[ ][ ]]
[[[*int_float_mixture ]][
Same as given by the traits class
[link numeric_conversion_traits_class_int_float_mixture int_float_mixture]
[link boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__ int_float_mixture]
]]
[[[*sign_mixture ]][
Same as given by the traits class
[link numeric_conversion_traits_class_sign_mixture sign_mixture]
[link boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__ sign_mixture]
]]
[[[*udt_builtin_mixture ]]
[Same as given by the traits class
[link numeric_conversion_traits_class_udt_builtin_mixture udt_builtin_mixture]
[link boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__ udt_builtin_mixture]
]]
]
The traits class provides the following __MPL_INTEGRAL_CONSTANT__\s of boolean type
which indicates indirectly the relation between the Source and Target ranges
(see [link numeric_conversion_definitions_range Definitions] for details).
(see [link boost_numericconversion.definitions.range_and_precision Definitions] for details).
[table
[[ ][ ]]
[[subranged ][
Same as given by [link numeric_conversion_traits_is_subranged is_subranged]
Same as given by [link boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__ is_subranged]
]]
[[trivial][
Indicates if both Source and Target, [_without cv-qualifications], are the same type.
@@ -230,7 +214,7 @@ The template parameter `S` without cv-qualifications
This type is either source_type or `source_type const&`.
It represents the optimal argument type for the
[link numeric_conversion_converter converter] member functions.
[link boost_numericconversion.converter___function_object converter] member functions.
If S is a built-in type, this is `source_type`, otherwise, this is `source_type const&`.
]]
@@ -238,7 +222,7 @@ If S is a built-in type, this is `source_type`, otherwise, this is `source_type
This type is either target_type or target_type const&
It represents the return type of the
[link numeric_conversion_converter converter] member functions.
[link boost_numericconversion.converter___function_object converter] member functions.
If `T==S`, it is `target_type const&`, otherwise, it is `target_type`.
]]
-279
View File
@@ -1,279 +0,0 @@
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<LINK REL="stylesheet" TYPE="text/css" HREF="../../../../boost.css">
<TITLE>Boost Numeric Conversion Library - Policy-based Converter</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000ff" VLINK="#800080">
<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
SUMMARY="header">
<TR>
<TD VALIGN="top" WIDTH="300"> <H3><A HREF="http://www.boost.org"><IMG
HEIGHT="86" WIDTH="277" ALT="C++ Boost" SRC="../../../../boost.png"
BORDER="0"></A> </H3>
</TD>
<TD VALIGN="top"> <H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1><A HREF="http://www.boost.org">Header </A><A
HREF="../../../../boost/numeric/conversion/converter.hpp">boost/numeric/conversion/converter.hpp</A></H1>
</TD>
</TR>
</TABLE>
<HR>
<H2>Contents</H2>
<DT><A HREF="#synopsis">Synopsis</A></DT>
<DT><A HREF="requirements.html">User Defined Types support</A></DT>
<DT><A HREF="#rchklogic">Range Checking Logic</A></DT>
<DT><A HREF="#examples">Examples</A></DT>
<HR>
<H2><A NAME="synopsis">Synopsis</A></H2>
<PRE>namespace boost { namespace numeric {
template&lt;class T,
class S,
class Traits, = conversion_traits&lt;T,S&gt;
class OverflowHandler = def_overflow_handler,
class Float2IntRounder = Trunc&lt; typename Traits::source_type &gt;,
class RawConverter = raw_converter&lt;Traits&gt;,
class UserRangeChecker = UseInternalRangeChecker
&gt;
struct converter
{
typedef Traits traits ;
typedef typename Traits::source_type source_type ;
typedef typename Traits::argument_type argument_type ;
typedef typename Traits::result_type result_type ;
static result_type convert ( argument_type s ) ;
result_type operator() ( argument_type s ) const ;
// Internal member functions:
static range_check_result out_of_range ( argument_type s ) ;
static void validate_range ( argument_type s ) ;
static result_type low_level_convert ( argument_type s ) ;
static source_type nearbyint ( argument_type s ) ;
} ;
} } // namespace numeric, boost
</PRE>
<P><code>boost::numeric::converter&lt;&gt;</code> is a
<a href="http://www.sgi.com/tech/stl/UnaryFunction.html">Unary Function Object</a>
encapsulating the code to perform a numeric conversion with the direction and properties specified
by the <CODE>Traits</CODE> template parameter. It can optionally take some
<A HREF="converter_policies.html">policies</a>
which can be used to customize its behavior. The Traits parameter is not a policy but
the parameter that defines the conversion.
</P>
<hr>
<h2>Template parameters:</h2>
<TABLE BORDER="1">
<TR>
<TD>&nbsp;T</TD>
<TD>&nbsp;The <A HREF="definitions.html#numtypes">Numeric Type</A> which is
the <i>Target</i> of the conversion.</TD>
</TR>
<TR>
<TD>&nbsp;S</TD>
<TD>&nbsp;The <A HREF="definitions.html#numtypes">Numeric Type</A> which is
the <i>Source</i> of the conversion.</TD>
</TR>
<TR>
<TD>&nbsp;<CODE>Traits</CODE>&nbsp;</TD>
<TD>&nbsp;This must be a conversion traits class with the interface of
<A HREF="conversion_traits.html">boost::numeric::conversion_traits</A>
</TD>
</TR>
<TR>
<TD>&nbsp;<A HREF="converter_policies.html#oh"><CODE>OverflowHandler</CODE></A>&nbsp;</TD>
<TD>&nbsp;<B>Stateless Policy</B> called to administrate the result of the
range checking.<br>
&nbsp;It is a <b>Function Object</b> which receives the result of <CODE>out_of_range()</CODE>
and is called inside the <CODE>validate_range()</CODE> static member function
exposed by the converter.</TD>
</TR>
<TR>
<TD>&nbsp;<A HREF="converter_policies.html#f2i"><CODE>Float2IntRounder</CODE></A>&nbsp;</TD>
<TD>&nbsp;<B>Stateless Policy</B> which specifies the rounding mode used for
float to integral conversions.<br>
&nbsp;It supplies the <CODE>nearbyint()</CODE> static member function exposed
by the converter.</TD>
</TR>
<TR>
<TD>&nbsp;<A HREF="converter_policies.html#rawc"><CODE>RawConverter</CODE></A>&nbsp;</TD>
<TD>&nbsp;<B>Stateless Policy</B> which is used to perform the actual conversion.
<br>
&nbsp;It supplies the<CODE> low_level_convert()</CODE> static member function
exposed by the converter.</TD>
</TR>
<TR>
<TD>&nbsp;<A HREF="converter_policies.html#rc"><CODE>UserRangeChecker</CODE></A>&nbsp;</TD>
<TD><i>Special and Optional</i> <b>Stateless Policy</b> which can be used to override
the internal range checking logic.<br>
If given, supplies alternative code for the out_of_range() and validate_range()
static member functions exposed by the converter.</TD>
</TR>
</TABLE>
<br>
<hr>
<h2>Member functions:</h2>
<P><CODE>static result_type converter&lt;&gt;::convert ( argument_type s ) ; //
throw</CODE></P>
<BLOCKQUOTE>
<P>This static member function converts an rvalue of type source_type to an rvalue
of type target_type.<BR>
If the conversion requires it, it performs a range checking before the conversion
and passes the result of the check to the overflow handler policy (the default
policy throws an exception if out-of-range is detected)<BR>
The implementation of this function is actually built from the policies and
is basically as follows:</P>
<PRE> result_type converter<>::convert ( argument_type s )
{
validate_range(s); // Implemented by the internal range checking logic
// (which also calls the OverflowHandler policy)
// or externally supplied by the UserRangeChecker policy.
s = nearbyint(s); // Externally supplied by the Float2IntRounder policy.
// NOTE: This is actually called only for float to int conversions.
return low_level_convert(s); // Externally supplied by the RawConverter policy.
}
</PRE>
<P>&quot;converter&lt;&gt;::operator() const&quot; just calls <CODE>convert()</CODE></P>
</BLOCKQUOTE>
<P><CODE>static range_check_result numeric_converter&lt;&gt;::out_of_range (
argument_type s ) ;</CODE></P>
<BLOCKQUOTE>
<P>This <A HREF="#int">internal</A> static member function determines if the
value 's' can be represented by the target type without overflow. <BR>
It does not determine if the conversion is <EM>exact</EM>; that is, it does
not detect <i>inexact</i> conversions, only <i>out-of-range</i> conversions
(see the <a href="definitions.html#roundoff">Definitions</a> for further details).<BR>
The return value is of enum type
<A HREF="converter_policies.html#rcr"><CODE>boost::numeric::range_check_result</CODE></A><BR>
The actual code for the range checking logic is optimized for the combined
properties of the source and target types. For example, a non-subranged conversion
(i.e: int-&gt;float), requires no range checking, so out_of_range() returns
cInRange directly. See the following <A HREF="#rchklogic">table</A> for more
details.<br>
If the user supplied a <a href="converter_policies.html#rc">UserRangeChecker</a>
policy, is this policy which implements this function, so the implementation
is user defined, although it is expected to perform the same conceptual check
and return the appropriate result.</P>
</BLOCKQUOTE>
<P><CODE>static void numeric_converter&lt;&gt;::validate_range ( argument_type
s ) ; // no throw</CODE></P>
<BLOCKQUOTE>
<P>This <A HREF="#int">internal</A> static member function calls <CODE>out_of_range(s)</CODE>,
and passes the result to the <A
HREF="converter_policies.html#oh"><CODE>OverflowHandler</CODE></A> policy class
<BR>
For those Target/Source combinations which don't require range checking, this
is an <U>empty inline function</U>.<br>
If the user supplied a <a href="converter_policies.html#rc">UserRangeChecker</a>
policy, is this policy which implements this function, so the implementation
is user defined, although it is expected to perform the same action as the
default. In particular, it is expected to pass the result of the check to
the overflow handler.</P>
</BLOCKQUOTE>
<P><CODE>static result_type numeric_converter&lt;&gt;::low_level_convert (
argument_type s ) ;</CODE></P>
<BLOCKQUOTE>
<P>This <A HREF="#int">internal</A> static member function performs the actual
conversion.<BR>
This function is externally supplied by the <A
HREF="converter_policies.html#rawc"><CODE>RawConverter</CODE></A> policy class.</P>
</BLOCKQUOTE>
<P><CODE>static source_type converter&lt;&gt;::nearbyint (
argument_type s ) ;</CODE></P>
<BLOCKQUOTE>
<P>This <A HREF="#int">internal</A> static member function, which is <U>only
used</U> for float to int conversions, returns an <I>integer value of <U>floating-point
type</U></I> according to some rounding direction. <BR>
This function is externally supplied by the <A
HREF="converter_policies.html#f2i"><CODE>Float2IntRounder</CODE></A> policy class
which encapsulates the specific rounding mode.</P>
</BLOCKQUOTE>
<hr>
<P><A NAME="int"><B>Internal Member Functions</B>:</A> These static member functions
build the actual conversion code used by <CODE>convert()</CODE>. The user does
not have to call these if calling convert(), since convert() calls them infernally,
but they can be called separately for specific needs.</P>
<hr>
<H2><A NAME="rchklogic">Range Checking Logic</A></H2>
<P>The Following table summarizes the internal range checking logic performed
for each combination of the properties of Source and Target.<br>
LowestT/HighestT denotes the highest and lowest values of the Target type, respectively.<br>
S(n) is short for &quot;static_cast&lt;S&gt;(n)&quot; (S denotes the Source
type).<br>
&quot;NONE&quot; indicates that for this case there is no range checking.</P>
<Pre>&nbsp; int_to_int |--> sig_to_sig |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) )
| |--> not subranged |--> NONE
|
|--> unsig_to_unsig |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) )
| |--> not subranged |--> NONE
|
|--> sig_to_unsig |--> pos subranged |--> ( s >= S(0) ) && ( s <= S(HighestT) )
| |--> not pos subranged |--> ( s >= S(0) )
|
|--> unsig_to_sig |--> subranged |--> ( s <= S(HighestT) )
| |--> not subranged |--> NONE
int_to_float |--> NONE
float_to_int |--> round_to_zero |--> ( s > S(LowestT)-S(1) ) && ( s < S(HighestT)+S(1) )
|--> round_to_even_nearest |--> ( s >= S(LowestT)-S(0.5) ) && ( s &lt; S(HighestT)+S(0.5) )
|--> round_to_infinity |--> ( s > S(LowestT)-S(1) ) && ( s <= S(HighestT) )
|--> round_to_neg_infinity |--> ( s >= S(LowestT) ) && ( s < S(HighestT)+S(1) )
float_to_float |--> subranged |--> ( s >= S(LowestT) ) && ( s <= S(HighestT) )
|--> not subranged |--> NONE
</Pre>
<HR>
<H2><A NAME="examples">Examples</A></H2>
<BLOCKQUOTE>
<PRE> #include &lt;cassert&gt;
#include &lt;boost/numeric/conversion/converter.hpp&gt;
int main() {
typedef boost::numeric::converter&lt;int,double&gt; Double2Int ;
int x = Double2Int::convert(2.0);
assert ( x == 2 );
int y = Double2Int()(3.14); // As a function object.
assert ( y == 3 ) ; // The default rounding is trunc.
try
{
double m = boost::numeric::bounds&lt;double&gt;::highest();
int z = Double2Int::convert(m); // By default throws positive_overflow()
}
catch ( boost::numeric::positive_overflow const&amp; )
{
}
return 0;
}</PRE>
</BLOCKQUOTE>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 16 May 2005</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
+12 -16
View File
@@ -8,8 +8,6 @@
http://www.boost.org/LICENSE_1_0.txt)
]
[#numeric_conversion_converter]
[section converter<> function object]
[section Synopsis]
@@ -52,7 +50,7 @@
`boost::numeric::converter<>` is a __SGI_UNARY_FUNCTION__ encapsulating
the code to perform a numeric conversion with the direction and
properties specified by the Traits template parameter. It can optionally
take some [link numeric_coversion_converter_policies policies] which can be used to customize its behavior. The
take some [link boost_numericconversion.numeric_converter_policy_classes policies] which can be used to customize its behavior. The
`Traits` parameter is not a policy but the parameter that defines
the conversion.
@@ -63,16 +61,16 @@ the conversion.
[table
[[ ][ ]]
[[`T`][
The [link numeric_conversion_definitions_numeric_types Numeric Type]
The [link boost_numericconversion.definitions.numeric_types Numeric Type]
which is the ['Target] of the conversion.
]]
[[`S`][
The [link numeric_conversion_definitions_numeric_types Numeric Type]
The [link boost_numericconversion.definitions.numeric_types Numeric Type]
which is the ['Source] of the conversion.
]]
[[`Traits`][
This must be a conversion traits class with the interface of
[link numeric_conversion_traits `boost::numeric::conversion_traits`]
[link boost_numericconversion.conversion_traits___traits_class `boost::numeric::conversion_traits`]
]]
[[`OverflowHandler`][
[*Stateless Policy] called to administrate the result of the range checking.
@@ -143,19 +141,19 @@ represented by the target type without overflow.
It does not determine if the conversion is ['exact]; that is, it does not detect
['inexact] conversions, only ['out-of-range] conversions (see the
[link numeric_conversion_definitions_roundoff Definitions] for further details).
[link boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations Definitions] for further details).
The return value is of enum type
[link numeric_conversion_converter_policies_range_check_result `boost::numeric::range_check_result`]
[link boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result `boost::numeric::range_check_result`]
The actual code for the range checking logic is optimized for the combined
properties of the source and target types. For example, a non-subranged
conversion (i.e: `int`->`float`), requires no range checking, so `out_of_range()`
returns `cInRange` directly. See the following
[link numeric_conversion_converter_range_checking_logic table] for more details.
[link boost_numericconversion.converter___function_object.range_checking_logic table] for more details.
If the user supplied a
[link numeric_conversion_policy_user_range_checker UserRangeChecker] policy,
[link boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker UserRangeChecker] policy,
is this policy which implements this function, so the implementation is user
defined, although it is expected to perform the same conceptual check and
return the appropriate result.
@@ -167,14 +165,14 @@ __SPACE__
This [link numeric_conversion_converter_internal internal] static member function
calls out_of_range(s), and passes the
result to the [link numeric_conversion_policy_overflow_handler OverflowHandler]
result to the [link boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler OverflowHandler]
policy class.
For those Target/Source combinations which don't require range checking, this
is an empty inline function.
If the user supplied a
[link numeric_conversion_policy_user_range_checker UserRangeChecker] policy,
[link boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker UserRangeChecker] policy,
is this policy which implements this function, so the implementation is user
defined, although it is expected to perform the same action as the default.
In particular, it is expected to pass the result of the check to the overflow handler.
@@ -187,7 +185,7 @@ This [link numeric_conversion_converter_internal internal] static member functio
performs the actual conversion.
This function is externally supplied by the
[link numeric_conversion_policy_raw_converter RawConverter] policy class.
[link boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter RawConverter] policy class.
__SPACE__
@@ -199,7 +197,7 @@ which is [_only used] for
type]] according to some rounding direction.
This function is externally supplied by the
[link numeric_conversion_policy_float_to_int_rounder Float2IntRounder] policy class
[link boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder Float2IntRounder] policy class
which encapsulates the specific rounding mode.
__SPACE__
@@ -214,8 +212,6 @@ them infernally, but they can be called separately for specific needs.
[endsect]
[#numeric_conversion_converter_range_checking_logic]
[section Range Checking Logic]
The following table summarizes the internal range checking logic performed for
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<H1><A HREF="http://www.boost.org">Header </A><A
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<HR>
<H2>Contents</H2>
<ol>
<LI><A HREF="#rcr"><CODE>enumeration range_check_result</CODE></A> </LI>
<LI><A HREF="#oh"><CODE>Policy OverflowHandler</CODE></A>
<UL>
<LI>class <A HREF="#oh_silent"><CODE>silent_overflow_handler</CODE></A></LI>
<LI>class <A HREF="#oh_def"><CODE>def_overflow_handler</CODE></A> (Default Policy)</LI>
<ul>
<LI>class <CODE> <A HREF="#bad_numc">bad_numeric_cast</A></CODE> <a href="#x-note">(see IMPORTANT note)</a></LI>
<LI>class <A HREF="#negovr"><CODE>negative_overflow</CODE></A></LI>
<LI>class <A HREF="#posovr"><CODE>positive_overflow</CODE></A></LI>
</ul>
</UL>
</LI>
<LI><A HREF="#f2i"><CODE>Policy FloatToIntRounder</CODE></A> <UL>
<LI>class <A HREF="#trunc"><CODE>Trunc&lt;T&gt;</CODE></A> (Default Policy)</LI>
<LI>class <A HREF="#round"><CODE>RoundEven&lt;T&gt;</CODE></A></LI>
<LI>class <A HREF="#ceil"><CODE>Ceil&lt;T&gt;</CODE></A></LI>
<LI>class <A HREF="#floor"><CODE>Floor&lt;T&gt;</CODE></A></LI>
</UL>
</LI>
<LI><A HREF="#rawc"><CODE>Policy RawConverter</CODE></A><UL>
<LI>class <A HREF="#rawnumc"><CODE>raw_converter class</CODE></A> (Default)</LI>
</UL>
</LI>
<LI><A HREF="#rc"><CODE>Policy UserRangeChecker</CODE></A><UL>
<LI>class <A HREF="#int_rc"><CODE>UseInternalRangeChecker class</CODE></A> (Default)</LI>
</UL>
</LI>
</ol>
<HR>
<H2><A NAME="types">Types</A></H2>
<H2><A NAME="rcr"><CODE>enum range_check_result</CODE></A></H2>
<PRE>namespace boost { namespace numeric {
enum range_check_result
{
cInRange ,
cNegOverflow ,
cPosOverflow
} ;
} }</PRE>
<P>Defines the values returned by <CODE>boost::numeric::converter&lt;&gt;::out_of_range()</CODE>
</P>
<HR>
<H2><A NAME="oh">Policy <CODE>OverflowHandler</CODE></A></H2>
<P>This <EM>stateless</EM> non-template policy class must be a <I>function object</I>
and is called to administrate the result of the range checking. It can throw
an exception if overflow has been detected by the range checking as indicated
by its argument. If it throws, is is recommended that it be <CODE>std::bad_cast</CODE>
or derived.</P>
<P>It must have the following interface (it does not has to be a template class):</P>
<PRE> struct YourOverflowHandlerPolicy
{
void operator() ( boost::range_check_result ) ; // throw bad_cast or derived
} ;
</PRE>
<P>It is called with the result of the converter's <CODE>out_of_range()</CODE>
inside <CODE>validate_range()</CODE>.</P>
<P>These are the two overflow handler classes provided by the
library:</P>
<PRE>namespace boost { namespace numeric {
struct <A NAME="oh_def">def_overflow_handler</a>
{
void operator() ( range_check_result r ) // throw bad_numeric_conversion derived
{
if ( r == cNegOverflow )
throw negative_overflow() ;
else if ( r == cPosOverflow )
throw positive_overflow() ;
}
} ;
struct <A NAME="oh_silent">silent_overflow_handler</a>
{
void operator() ( range_check_result ) // no-throw
{}
} ;
} }
</PRE>
<P>And these are the Exception Classes thrown by the default
overflow handler <a href="#x-note">(see IMPORTANT note)</a></P>
<PRE>namespace boost { namespace numeric {
class <a name="bad_numc">bad_numeric_cast</a> : public std::bad_cast
{
public:
virtual const char *what() const // throw()
{ return &quot;bad numeric conversion: overflow&quot;; }
};
class <a name="negovr">negative_overflow</a> : public bad_numeric_cast
{
public:
virtual const char *what() const // throw()
{ return &quot;bad numeric conversion: negative overflow&quot;; }
};
class <a name="posovr">positive_overflow</a> : public bad_numeric_cast
{
public:
virtual const char *what() const // throw()
{ return &quot;bad numeric conversion: positive overflow&quot;; }
};
} }
</PRE>
<a name="x-note"><p><b>IMPORTANT RELEASE NOTE for 1.33</b></p></a>
<blockquote>
<p>Previous to boost version 1.33, the exception class <code>bad_numeric_cast</code> was
named <code>bad_numeric_conversion</code>. However, in 1.33, the old function
<code>numeric_cast&lt;&gt;</code> from <code>boost/cast.hpp</code> was completly replaced by the new
<code>numeric_cast&lt;&gt;</code> in <code>boost/numeric/conversion/cast.hpp</code>
(and <code>boost/cast.hpp</code> is including <code>boost/numeric/conversion/cast.hpp</code> now). That old function which
existed in boost for quite some time used the <code>bad_numeric_cast</code> as its
exception type so I decided to avoid backward compatibility problems by adopting it (guessing
that the user base for the old code is wider than for the new code).</p>
</blockquote>
<HR>
<H2><A NAME="f2i">Policy <CODE>FloatToIntRounder</CODE></A></H2>
<P>This <EM>stateless</EM> template policy class specifies the rounding mode used
for<U> float to integral</U> conversions. It supplies the <CODE>&quot;nearbyint()&quot;</CODE>
static member function exposed by the converter, which means that it <U>publicly
inherits from this policy.</U></P>
<P>The policy must have the following interface:</P>
<PRE> template&lt;class S&gt;
struct YourFloat2IntRounderPolicy
{
typedef S source_type ;
typedef <I>{S or S const&amp;}</I> argument_type ;
static source_type nearbyint ( argument_type s ) { ... }
typedef mpl::integral_c&lt;std::float_round_style,std::<i>round_...</i>&gt; round_style ;
} ;
</PRE>
<P>These are the rounder classes provided by the library:</P>
<BLOCKQUOTE>
<P><EM>NOTE: These classes are not intended to be general purpose rounding functions
but specific policies for converter&lt;&gt;. This is why <U>they are not function
objects</U>.</EM></P>
<P>(only the specific parts are shown, see the general policy form above)</P>
<PRE>namespace boost { namespace numeric {
<A NAME="trunc"></A>template&lt;class S&gt;
struct Trunc
{
static source_type nearbyint ( argument_type s )
{
using std::floor ;
using std::ceil ;
return s >= static_cast&lt;S&gt;(0) ? floor(s) : ceil(s) ;
}
typedef mpl::integral_c&lt;std::float_round_style,std::round_toward_zero&gt; round_style ;
} ;
</PRE>
<PRE> <A NAME="round"></A>template&lt;class S&gt;
struct RoundEven
{
static source_type nearbyint ( argument_type s )
{
return <i>impl-defined-value</i> ;
}
typedef mpl::integral_c&lt;std::float_round_style,std::round_to_nearest&gt; round_style ;
} ;
</PRE>
<PRE> <A NAME="ceil"></A>template&lt;class S&gt;
struct Ceil
{
static source_type nearbyint ( argument_type s )
{<br> using std::ceil ;<br> return ceil(s) ;<br> }
typedef mpl::integral_c&lt;std::float_round_style,std::round_toward_infinity&gt; round_style ;
} ;
</PRE>
<PRE> <A NAME="floor"></A>template&lt;class S&gt;
struct Floor
{
static source_type nearbyint ( argument_type s )
{<br> using std::floor ;<br> return floor(s) ;<br> }
typedef mpl::integral_c&lt;std::float_round_style,std::round_toward_neg_infinity&gt; round_style ;
} ;
} } // namespace numeric, namespace boost</PRE>
</BLOCKQUOTE>
<H3>Math Functions used by the rounder policies</H3>
<P>The rounder policies supplied by this header use math functions floor() and
ceil(). The standard versions of these functions are introduced in context by
a using directive, so in normal conditions, the standard functions will be used.
<br>
However, if there are other visible corresponding overloads an ambiguity could
arise. In this case, the user can supply her own rounder policy which could,
for instance, use a fully qualified call.<br>
This technique allows the default rounder policies to be used directly with
user defined types. The user only requires that suitable overloads of floor()
and ceil() be visible. See also <a HREF="requirements.html">User Defined Numeric Types support</a><br>
</P>
<HR>
<H2><A NAME="rawc">Policy <CODE>RawConverter</CODE></A></H2>
<P>This <EM>stateless</EM> template policy class is used to perform the actual
conversion from Source to Target. It supplies the <CODE>&quot;low_level_convert()&quot;</CODE>
static member function exposed by the converter, which means that it <U>publicly
inherits from this policy.</U></P>
<P>The policy must have the following interface:</P>
<PRE> template&lt;class Traits&gt;
struct YourRawConverterPolicy
{
typedef typename Traits::result_type result_type ;
typedef typename Traits::argument_type argument_type ;
static result_type low_level_convert ( argument_type s ) { return <I>&lt;impl defined&gt;</I> ; }
} ;
</PRE>
<P>This policy is mostly provided as a hook for user defined types which don't
support <CODE>static_cast&lt;&gt;</CODE> conversions to some types</P>
<P>This is the only raw converter policy class provided
by the library:</P>
<PRE>namespace boost { namespace numeric {
template&lt;class Traits&gt;
struct <A NAME="rawnumc">raw_numeric_converter</A>
{
typedef typename Traits::result_type result_type ;
typedef typename Traits::argument_type argument_type ;
static result_type low_level_convert ( argument_type s )
{ return static_cast&lt;result_type&gt;(s) ; }
} ;
}
</PRE>
<HR>
<H2><A NAME="rc">Policy <CODE>UserRangeChecker</CODE></A></H2>
<P>This <EM>stateless</EM> template policy class is used -<u>only if supplied</u>-
to <b>override</b> the internal range checking logic.<br>
It supplies the <CODE>&quot;validate_range()&quot;</CODE> static member function
exposed by the converter, which means that it <U>publicly inherits from this
policy.</U></P>
<P>The policy must have the following interface:</P>
<PRE> template&lt;class Traits&gt;
struct YourRangeCheckerPolicy
{
typedef typename Traits::argument_type argument_type ;
// Determines if the value 's' fits in the range of the Target type.
static range_check_result out_of_range ( argument_type s ) ;
// Checks whether the value 's' is out_of_range()
// and passes the result of the check to the OverflowHandler policy.
static void validate_range ( argument_type s )
{
OverflowHandler()( out_of_range(s) ) ;
}
} ;
</PRE>
<P>This policy is <b>only</b> provided as a hook for user defined types which
require range checking (which is disabled by default when a UDT is involved).<br>
The library provides a class: <A NAME="int_rc"><code>UseInternalRangeChecker{};</code></a> which
is a <i>fake</i> RangeChecker policy used to signal the converter to use its
internal range checking implementation.
</P>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 23 June 2004</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
+1 -13
View File
@@ -8,13 +8,9 @@
http://www.boost.org/LICENSE_1_0.txt)
]
[#numeric_coversion_converter_policies]
[section Numeric Converter Policy Classes]
[#numeric_conversion_converter_policies_range_check_result]
[section enum range_check_result]
namespace boost { namespace numeric {
@@ -32,8 +28,6 @@ Defines the values returned by `boost::numeric::converter<>::out_of_range()`
[endsect]
[#numeric_conversion_policy_overflow_handler]
[section Policy OverflowHandler]
This ['stateless] non-template policy class must be a ['function object] and is
@@ -128,8 +122,6 @@ the old code is wider than for the new code).
[endsect]
[#numeric_conversion_policy_float_to_int_rounder]
[section Policy Float2IntRounder]
This ['stateless] template policy class specifies the rounding mode used
@@ -227,13 +219,11 @@ use a fully qualified call.
This technique allows the default rounder policies to be used directly with
user defined types. The user only requires that suitable overloads of `floor()` and `ceil()`
be visible. See also [link numeric_conversion_requirements User Defined Numeric Types]
be visible. See also [link boost_numericconversion.type_requirements_and_user_defined_types_support User Defined Numeric Types]
support.
[endsect]
[#numeric_conversion_policy_raw_converter]
[section Policy RawConverter]
This ['stateless] template policy class is used to perform the
@@ -275,8 +265,6 @@ This is the only raw converter policy class provided by the library:
[endsect]
[#numeric_conversion_policy_user_range_checker]
[section Policy UserRangeChecker]
This ['stateless] template policy class is used [_only if supplied]
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<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1 ALIGN="center">Definitions</H1>
</TH>
</TR>
</TABLE>
<HR>
<H2>Contents</H2>
<DL CLASS="page-index">
<dt><A HREF="#intro">Introduction</A></dt>
<dt><A HREF="#typeval">Types and Values</A></dt>
<dt><A HREF="#stdtypes">C++ Arithmetic Types</A></dt>
<dt><A HREF="#numtypes">Numeric Types</A></dt>
<dt><A HREF="#range">Range and Precision</A></dt>
<dt><A HREF="#roundoff">Exact, Correctly Rounded and Out-Of-Range Representations</A></dt>
<dt><A HREF="#stdconv">Standard (numeric) Conversions</A></dt>
<dt><A HREF="#subranged">Subranged Conversion Direction, Subtype and Supertype</A></dt>
</DL>
<h2><A NAME="intro">Introduction</A></h2>
<P>This section provides definitions of terms used in the Numeric Conversion library.</p>
<p><b>Notation:</b>
<li><u>underlined text</u> denotes terms defined in the C++ standard.</li>
<li><b>bold face</b> denotes terms defined here but not in the standard.</li>
<p></p>
<hr>
<h2><A NAME="typeval">Types and Values</A></h2>
<p>As defined by the <u>C++ Object Model</u> (&sect;1.7) the <u>storage</u> or
memory on which a C++ program runs is a contiguous sequence of <u>bytes</u>
where each byte is a contiguous sequence of <u>bits</u>.<br>
An <u>object</u> is a region of storage (&sect;1.8) and has a type (&sect;3.9).<br>
A <u>type</u> is a discrete set of values. <br>
An object of type T has an <u>object representation</u> which is the sequence
of bytes stored in the object (&sect;3.9/4)<br>
An object of type T has a <u>value representation</u> which is the set of bits
that determine the <i>value</i> of an object of that type (&sect;3.9/4). For
<u>POD</u> types (&sect;3.9/10), this bitset is given by the object representation,
but not all the bits in the storage need to participate in the value representation
(except for character types): for example, some bits might be used for padding
or there may be trap-bits.</p>
<p>The <b>typed value</b> that is held by an object is
the value which is determined by its value representation.<br>
An <b>abstract value</b> (untyped) is
the conceptual information that is represented in a type
(i.e. the number &pi;).<br>
The <b>intrinsic value</b> of an object is
the binary value of the sequence of unsigned characters which form its object representation.</p>
<p><i>Abstract values</i> can be <b>represented</b> in a given type.<br>
To <b>represent</b> an abstract value 'V' in a type 'T'
is to obtain a typed value 'v' which <i>corresponds</i> to the abstract value 'V'.<br>
The operation is denoted using the 'rep()' operator, as in: <code>v=rep(V)</code>.<br>
'v' is the <b>representation</b> of 'V' in the type 'T'.<br>
For example, the abstract value &pi; can be represented in the type <code>'double'</code> as the
'double value M_PI' and in the type <code>'int'</code> as the 'int value 3'</p>
<p>Conversely, <i>typed values</i> can be <b>abstracted</b>.<br>
To <b>abstract</b> a typed value 'v' of type 'T' is to obtain the
abstract value 'V' whose representation in 'T' is 'v'.<br>
The operation is denoted using the 'abt()' operator, as in: <code>V=abt(v)</code>.<br>
'V' is the <b>abstraction</b> of 'v' of type 'T'.<br>
Abstraction is just an abstract operation (you can't do it); but it is defined nevertheless
because it will be used to give the definitions in the rest of this document.</p>
<hr>
<h2><A NAME="stdtypes">C++ Arithmetic Types</A></h2>
<P>The C++ language defines <u>fundamental types</u> (&sect;3.9.1). The following
subsets of the fundamental types are intended to represent <i>numbers</i>:</p>
<li><u>signed integer types</u> (&sect;3.9.1/2):<br>
<blockquote>
<code>{signed char, signed short int, signed int, signed long int}</code><br>
Can be used to represent general integer numbers (both negative and positive).
</blockquote>
</li>
<li><u>unsigned integer types</u> (&sect;3.9.1/3):<br>
<blockquote>
<code>{unsigned char, unsigned short int, unsigned int, unsigned long int}</code><br>
Can be used to represent positive integer numbers <u>with modulo-arithmetic</u>.<br>
</blockquote>
<li><u>floating-point types</u> (&sect;3.9.1/8):<br>
<blockquote>
<code>{float,double,long double}</code><br>
Can be used to represent real numbers.
</blockquote>
</li>
<li><u>integral or integer types</u> (&sect;3.9.1/7):<br>
<blockquote>
<code>{{signed integers},{unsigned integers}, bool, char and wchar_t}</code>
</blockquote>
</li>
<li><u>arithmetic types</u> (&sect;3.9.1/8):<br>
<blockquote>
<code>{{integer types},{floating types}}</code>
</blockquote>
</li>
<P>The integer types are required to have a <i>binary</i> value representation.<br>
Additionally, the signed/unsigned integer types of the same base type (short, int or long)
are required to have the same value representation, that is:</P>
<pre> int i = -3 ; // suppose value representation is: 10011 (sign bit + 4 magnitude bits)
unsigned int u = i ; // u is required to have the same 10011 as its value representation.
</pre>
<P>In other words, the integer types signed/unsigned X use the same value representation
but a different <i>interpretation</i> of it; that is, their <i>typed values</i>
might differ.<br>
Another consequence of this is that the range for signed X is always a smaller subset
of the range of unsigned X, as required by &sect;3.9.1/3.</P>
<P>Note: always remember that unsigned types, unlike signed types, have modulo-arithmetic;
that is, they do not overflow.<br>
This means that:
<li> Always be extra careful when mixing signed/unsigned types</li>
<li> Use unsigned types only when you need modulo arithmetic or very very large numbers.
Don't use unsigned types just because you intend to deal with positive values only
(you can do this with signed types as well).</li>.
<p></P>
<hr>
<h2><A NAME="numtypes">Numeric Types</A></h2>
<p>This section introduces the following definitions intended to integrate arithmetic
types with user-defined types which behave like numbers. Some definitions are
purposely broad in order to include a vast variety of user-defined number
types.</p>
<p>Within this library, the term <i>number</i> refers to an abstract numeric value.</p>
<p>A type is <b>numeric</b> if:</p>
<li>It is an arithmetic type, or,</li>
<li>It is a user-defined type which</li>
<blockquote>
<li>Represents numeric abstract values (i.e. numbers).</li>
<li>Can be converted (either implicitly or explicitly) to/from at least one
arithmetic type.</li>
<li>Has <a href="#range">range</a> (possibly unbounded) and <a href="#range">precision</a>
(possibly dynamic or unlimited).</li>
<li>Provides an specialization of <code>std::numeric_limits</code>.</li>
</blockquote>
<p></p>
<p>A numeric type is <b>signed</b> if the abstract values it represent include negative numbers.<br>
A numeric type is <b>unsigned</b> if the abstract values it represent exclude negative numbers.<br>
A numeric type is <b>modulo</b> if it has modulo-arithmetic (does not overflow).<br>
A numeric type is <b>integer</b> if the abstract values it represent are whole numbers.<br>
A numeric type is <b>floating</b> if the abstract values it represent are real numbers.<br>
An <b>arithmetic value</b> is the typed value of an arithmetic type<br>
A <b>numeric value</b> is the typed value of a numeric type</p>
<p></p>
<p>These definitions simply generalize the standard notions of arithmetic types
and values by introducing a superset called <u>numeric</u>. All arithmetic types
and values are numeric types and values, but not vice versa, since user-defined
numeric types are not arithmetic types.</p>
<p>The following examples clarify the differences between arithmetic and numeric types (and values):</p>
<pre>// A numeric type which is not an arithmetic type (is user-defined)
// and which is intended to represent integer numbers (i.e., an 'integer' numeric type)
class MyInt
{
MyInt ( long long v ) ;
long long to_builtin();
} ;
namespace std {
template&lt;&gt; numeric_limits&lt;MyInt&gt; { ... } ;
}
// A 'floating' numeric type (double) which is also an arithmetic type (built-in),
// with a float numeric value.
double pi = M_PI ;
// A 'floating' numeric type with a whole numeric value.
// NOTE: numeric values are typed valued, hence, they are, for instance,
// integer or floating, despite the value itself being whole or including
// a fractional part.
double two = 2.0 ;
// An integer numeric type with an integer numeric value.
MyInt i(1234);
</pre>
<hr>
<h2><A NAME="range">Range and Precision</A></h2>
<p>Given a number set 'N', some of its elements are representable in a numeric type 'T'.<br>
The set of representable values of type 'T', or numeric set of 'T', is a set of numeric values
whose elements are the representation of some <i>subset</i> of 'N'.<br>
For example, the interval of 'int' values [INT_MIN,INT_MAX] is the set of representable values
of type 'int', i.e. the 'int' numeric set, and corresponds to the representation of the elements
of the interval of abstract values [abt(INT_MIN),abt(INT_MAX)] from the integer numbers.<br>
Similarly, the interval of 'double' values [-DBL_MAX,DBL_MAX] is the 'double' numeric set,
which corresponds to the subset of the real numbers from abt(-DBL_MAX) to abt(DBL_MAX).
</p>
<p>Let <b>next(x)</b> denote the lowest numeric value greater than x.<br>
Let <b>prev(x)</b> denote the highest numeric value lower then x.</p>
<p>Let <code><b>v=prev(next(V))</b></code> and <code><b>v=next(prev(V))</b></code> be identities that relate a numeric
typed value 'v' with a number 'V'.</p>
<p>An ordered pair of numeric values <i>x,y</i> s.t. <i>x&lt;y</i> are <b>consecutive</b> iff
<code>next(x)==y</code>.</p>
<p>The abstract distance between consecutive numeric values is usually referred
to as a <u>Unit in the Last Place</u>, or <b>ulp</b> for short. A ulp is a quantity whose abstract
magnitude is <i>relative</i> to the numeric values it corresponds to: If the numeric set is not evenly
distributed, that is, if the abstract distance between consecutive numeric values varies along the set
-as is the case with the floating-point types-, the magnitude of 1ulp after the numeric value x
might be (usually is) different from the magnitude of a 1ulp after the numeric value y for x!=y.</p>
<p>Since numbers are inherently ordered, a <b>numeric set</b> of type 'T'
is an ordered sequence of numeric values (of type 'T') of the form:
</p>
<p><code>REP(T)={l,next(l),next(next(l)),...,prev(prev(h)),prev(h),h}</code>
</p>
<p>where 'l' and 'h' are respectively the lowest and highest values of type 'T', called the
<b>boundary values</b> of type T.</p>
<p>A numeric set is discrete. It has a <b>size</b> which is the number
of numeric values in the set, a <b>width</b> which is the abstract difference between
the highest and lowest boundary values: [abt(h)-abt(l)], and a <b>density</b>
which is the relation between its size and width: 'density=size/width'.<br>
The integer types have density 1, which means that there are no unrepresentable integer numbers
between abt(l) and abt(h) (i.e. there are no gaps). On the other hand,
floating types have density much smaller than 1, which means that there are
real numbers unrepresented between consecutive floating values (i.e. there are gaps).
</p>
<p>The interval of <u>abstract values</u> [abt(l),abt(h)] is the <b>range</b> of the type 'T',
denoted 'R(T)'.<br>
A range is a set of abstract values and not a set of numeric values. In other
documents, such as the C++ standard, the word 'range' is <i>sometimes</i> used
as synonym for 'numeric set', that is, as the ordered sequence of numeric values
from 'l' to 'h'. In this document, however, a range is an abstract interval
which subtends the numeric set.<br>
For example, the sequence [-DBL_MAX,DBL_MAX] is the numeric set of the type 'double', and
the real interval [abt(-DBL_MAX),abt(DBL_MAX)] is its range.<br>
Notice, for instance, that the range of a floating-point type is <i>continuous</i> unlike
its numeric set.<br>
This definition was chosen because:
<li>(a) The discrete set of numeric values is already given by the numeric set.</li>
<li>(b) Abstract intervals are easier to compare and overlap since only boundary values
need to be considered.</li><br>
This definition allows for a concise definition of 'subranged' as given in the last section.<br>
The width of a numeric set, as defined, is exactly equivalent to the width of a range.
<p></p>
<p>The <b>precision</b> of a type is given by the width or density of the numeric set.<br>
For integer types, which have density 1, the precision is conceptually equivalent to the range
and is determined by the number of bits used in the value representation: The higher the
number of bits the bigger the size of the numeric set, the wider the range, and the higher
the precision.<br>
For floating types, which have density &lt;&lt;1, the precision is given not by the
width of the range but by the density. In a typical implementation,
the range is determined by the number of bits used in the exponent, and the precision by
the number of bits used in the mantissa (giving the maximum number of significant digits
that can be exactly represented). The higher the number of exponent bits the
wider the range, while the higher the number of mantissa bits, the higher the precision.
</p>
<hr>
<h2><A NAME="roundoff">Exact, Correctly Rounded and Out-Of-Range Representations</A></h2>
<p>Given an abstract value 'V' and a type 'T' with its corresponding range [abt(l),abt(h)]:</p>
<p>If <code>V &lt; abt(l)</code> or <code>V &gt; abt(h)</code>, 'V' is <b>not representable</b>
(cannot be represented) in the type T, or, equivalently, it's representation in the type 'T'
is <b>out of range</b>, or <b>overflows</b>.<br>
If <code>V &lt; abt(l)</code>, the <b>overflow is negative</b>.<br>
If <code>V &gt; abt(h)</code>, the <b>overflow is positive</b>.
</p>
<p>If <code>V &ge; abt(l)</code> and <code>V &le; abt(h)</code>,'V' is <b>representable</b>
(can be represented) in the type T, or, equivalently, its representation in the type 'T'
is in <b>in range</b>, or <b>does not overflow</b>.</p>
<p>Notice that a numeric type, such as a C++ unsigned type, can define that any 'V' does not
overflow by always representing not 'V' itself but the abstract value <code>U = [ V % (abt(h)+1) ]</code>,
which is always in range.</p>
<p>Given an abstract value 'V' represented in the type 'T' as 'v', the <b>roundoff</b> error
of the representation is the abstract difference: (abt(v)-V).<br>
Notice that a representation is an <i>operation</i>, hence, the roundoff error corresponds to
the representation operation and not to the numeric value itself (i.e. numeric values do not
have any error themselves)<br>
If the roundoff is 0, the representation is <b>exact</b>, and 'V' is <b>exactly representable</b>
in the type T.<br>
If the roundoff is not 0, the representation is <b>inexact</b>, and 'V' is <b>inexactly representable</b>
in the type T.</p>
<p>Given an abstract value 'V' representable in a type 'T', there are always two consecutive
numeric values of type 'T', 'prev' and 'next', such that <code>abt(prev) &le; V &le; abt(next)</code>.
These are called the <b>adjacents</b> of 'V' in the type 'T'.<br>
If a representation 'v' in a type 'T' -either exact or inexact-, is any of the adjacents of 'V'
in that type, that is, if <code>v==prev or v==next</code>, the representation is
<b>faithfully rounded</b>. If the choice between 'prev' and 'next'
matches a given <b>rounding direction</b>, it is <b>correctly rounded</b>.<br>
All exact representations are correctly rounded, but not all inexact representations are. In particular,
C++ requires numeric conversions (described below) and the result of arithmetic operations
(not covered by this document) to be correctly rounded, but batch operations propagate roundoff, thus
final results are usually incorrectly rounded, that is, the numeric value 'r' which is the computed
result is neither of the adjacents of the abstract value 'R' which is the theoretical result.<br>
Because a correctly rounded representation is always one of adjacents of the abstract value being
represented, the roundoff is guaranteed to be at most 1ulp.</p>
<P>The following examples summarize the given definitions. Consider:</p>
<li>A numeric type 'Int' representing integer numbers with a <i>numeric set</i>: {-2,-1,0,1,2}
and <i>range</i>: [-2,2]</li>.
<li>A numeric type 'Cardinal' representing integer numbers with a <i>numeric set</i>:
{0,1,2,3,4,5,6,7,8,9} and <i>range</i>: [0,9] (no modulo-arithmetic here)</li>.
<li>A numeric type 'Real' representing real numbers with a <i>numeric set</i>:
{-2.0,-1.5,-1.0,-0.5,-0.0,+0.0,+0.5,+1.0,+1.5,+2.0} and <i>range</i>: [-2.0,+2.0]</li>
<li>A numeric type 'Whole' representing real numbers with a <i>numeric set</i>:
{-2.0,-1.0,0.0,+1.0,+2.0} and <i>range</i>: [-2.0,+2.0]</li>
<p>First, notice that the types 'Real' and 'Whole' both represent real numbers, have the
same range, but different precision.</p>
<p>The integer number 1 (an abstract value) can be exactly represented in any of these types.<br>
The integer number -1 can be exactly represented in 'Int', 'Real' and 'Whole', but cannot
be represented in 'Cardinal', yielding negative overflow.<br>
The real number 1.5 can be exactly represented in 'Real', and inexactly represented in the
other types.<br>
If 1.5 is represented as either 1 or 2 in any of the types (except Real), the
representation is correctly rounded.<br>
If 0.5 is represented as +1.5 in the type 'Real', it is incorrectly rounded.<br>
(-2.0,-1.5) are the 'Real' adjacents of any real number in the interval [-2.0,-1.5],
yet there are no 'Real' adjacents for x &lt; -2.0, nor for x &gt; +2.0.
</p>
<hr>
<h2><A NAME="stdconv">Standard (numeric) Conversions</A></h2>
<P>The C++ language defines <u>Standard Conversions</u> (&sect;4) some of which are
conversions between arithmetic types.<br>
These are <u>Integral promotions</u> (&sect;4.5), <u>Integral conversions</u> (&sect;4.7),
<u>Floating point promotions</u> (&sect;4.6), <u>Floating point conversions</u> (&sect;4.8)
and <u>Floating-integral conversions</u> (&sect;4.9).<br>
In the sequel, integral and floating point promotions are called <b>arithmetic promotions</b>,
and these plus integral, floating-point and floating-integral conversions are called
<b>arithmetic conversions</b> (i.e, promotions are conversions).
</P>
<P>Promotions, both Integral and Floating point, are <i>value-preserving</i>, which means
that the typed value is not changed with the conversion.</p>
<p>In the sequel, consider a source typed value 's' of type 'S', the source abstract value 'N=abt(s)',
a destination type 'T'; and whenever possible, a result typed value 't' of type 'T'.</p>
<p>Integer to integer conversions are always defined:<br>
If 'T' is unsigned, the abstract value which is effectively represented is not 'N' but
'M=[ N % ( abt(h) + 1 ) ]', where 'h' is the highest unsigned typed value of type 'T'.<br>
If 'T' is signed and 'N' is not directly representable, the result 't' is
<u>implementation-defined</u>, which means that the C++ implementation is required to produce
a value 't' even if it is totally unrelated to 's'.</p>
<p>Floating to Floating conversions are defined only if 'N' is representable;
if it is not, the conversion has <u>undefined behavior.</u><br>
If 'N' is exactly representable, 't' is required to be the exact representation.<br>
If 'N' is inexactly representable, 't' is required to be one of the two adjacents, with
an implementation-defined choice of rounding direction; that is, the conversion is required
to be correctly rounded.</p>
<p>Floating to Integer conversions represent not 'N' but 'M=trunc(N)', were trunc() is to truncate: i.e.
to remove the fractional part, if any.<br>
If 'M' is not representable in 'T', the conversion has <u>undefined behavior</u>
(unless 'T' is bool, see &sect;4.12).</p>
<p>Integer to Floating conversions are always defined.<br>
If 'N' is exactly representable, 't' is required to be the exact representation.<br>
If 'N' is inexactly representable, 't' is required to be one of the two adjacents, with
an implementation-defined choice of rounding direction; that is, the conversion is required
to be correctly rounded.</p>
<hr>
<h2><A NAME="subranged">Subranged Conversion Direction, Subtype and Supertype</A></h2>
<P>Given a source type 'S' and a destination type 'T', there is a <b>conversion direction</b>
denoted: <code>'S-&gt;T'</code>.<br>
For any two ranges the following <i>range relation</i> can be defined: A range
'X' can be <i>entirely contained</i> in a range 'Y', in which case it is said that
'X' is enclosed by 'Y'.<br>
Formally: R(S) is <b>enclosed</b> by R(T) iif (R(S) intersection R(T)) == R(S).</P>
<P>If the source type range, R(S), is <i>not enclosed</i> in the target type range, R(T);
that is, if (R(S) &amp; R(T)) != R(S), the conversion direction is said to be <b>subranged</b>,
which means that R(S) is not entirely contained in R(T) and therefore there is
some portion of the source range which falls outside the target range. In other words,
if a conversion direction S->T is subranged, there are values in S which cannot be represented
in T because they are out of range.<br>
Notice that for S->T, the adjective subranged applies to 'T'.</p>
<p>Examples:<br>
Given the following numeric types all representing real numbers:<br>
<br>
X with numeric set {-2.0,-1.0,0.0,+1.0,+2.0} and range [-2.0,+2.0]<br>
Y with numeric set {-2.0,-1.5,-1.0,-0.5,0.0,+0.5,+1.0,+1.5,+2.0} and range [-2.0,+2.0]<br>
Z with numeric set {-1.0,0.0,+1.0} and range [-1.0,+1.0]<br>
<br>
For:<br>
<br>
(a) X->Y:
<blockquote>
R(X) & R(Y) == R(X), then X->Y is not subranged.
Thus, all values of type X are representable in the type Y.
</blockquote>
(b) Y->X:
<blockquote>
R(Y) & R(X) == R(Y), then Y->X is not subranged.
Thus, all values of type Y are representable in the type X, but in this case, some values
are <i>inexactly</i> representable (all the halves).<br>
(note: it is to permit this case that a range is an interval of abstract values
and not an interval of typed values)
</blockquote>
(b) X->Z:
<blockquote>
R(X) & R(Z) != R(X), then X->Z is subranged.
Thus, some values of type X are not representable in the type Z, they fall out of range
(-2.0 and +2.0)
</blockquote>
<p></p>
<p>It is possible that R(S) is not enclosed by R(T), while neither is R(T) enclosed
by R(S); for example, UNSIG=[0,255] is not enclosed by SIG=[-128,127]; neither is SIG
enclosed by UNSIG.<br>
This implies that is possible that a conversion direction is subranged both
ways. This occurs when a mixture of signed/unsigned types are involved and indicates
that in both directions there are values which can fall out of range.</P>
<P>Given the range relation (subranged or not) of a conversion direction S-&gt;T,
it is possible to classify 'S' and 'T' as <b>supertype</b> and <b>subtype</b>:<br>
If the conversion is subranged, which means that 'T' cannot represent all possible values of type 'S',
'S' is the supertype and 'T' the subtype; otherwise, 'T' is the supertype and 'S' the subtype.<br>
<br>
For example:<br>
R(float)=[-FLT_MAX,FLT_MAX] and R(double)=[-DBL_MAX,DBL_MAX].<br>
If FLT_MAX < DBL_MAX:<br>
'double->float' is subranged and supertype=double, subtype=float.<br>
'float->double' is not subranged and supertype=double, subtype=float.<br>
Notice that while 'double->float' is subranged, 'float->double' is not,
which yields the same supertype,subtype for both directions.<br>
<br>
Now consider:<br>
R(int)=[INT_MIN,INT_MAX] and R(unsigned int)=[0,UINT_MAX].<br>
A C++ implementation is required to have UINT_MAX > INT_MAX (&sect;3.9/3), so:<br>
'int->unsigned' is subranged (negative values fall out of range) and supertype=int, subtype=unsigned.<br>
'unsigned->int' is <em>also</em> subranged (high positive values fall out of range)
and supertype=unsigned, subtype=int.<br>
In this case, the conversion is subranged in both directions and the supertype,subtype pairs
are not invariant (under inversion of direction). This indicates that none of the types can
represent all the values of the other.</p>
<p>When the supertype is the same for both 'S->T' and 'T->S', it is effectively indicating
a type which can represent all the values of the subtype.<br>
Consequently, if a conversion X->Y is not subranged, but the opposite (Y->X)
is, so that the supertype is always 'Y', it is said that the direction X->Y
is <b>correctly rounded value preserving</b>, meaning that all such conversions
are guaranteed to produce results in range and correctly rounded (even if inexact).<br>
For example, all integer to floating conversions are correctly rounded value preserving.
</p>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 23 June 2004</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</body>
</HTML>
+2 -12
View File
@@ -85,8 +85,6 @@ rest of this document.
[endsect]
[#numeric_conversion_cpp_arithmetic_types]
[section C++ Arithmetic Types]
The C++ language defines [_fundamental types] (§3.9.1). The following subsets of
@@ -144,8 +142,6 @@ positive values only (you can do this with signed types as well).
[endsect]
[#numeric_conversion_definitions_numeric_types]
[section Numeric Types]
This section introduces the following definitions intended to integrate
@@ -161,8 +157,8 @@ A type is [*numeric] if:
* It is a user-defined type which
* Represents numeric abstract values (i.e. numbers).
* Can be converted (either implicitly or explicitly) to/from at least one arithmetic type.
* Has [link numeric_conversion_definitions_range range] (possibly unbounded)
and [link numeric_conversion_definitions_range precision] (possibly dynamic or
* Has [link boost_numericconversion.definitions.range_and_precision range] (possibly unbounded)
and [link boost_numericconversion.definitions.range_and_precision precision] (possibly dynamic or
unlimited).
* Provides an specialization of `std::numeric_limits`.
@@ -216,8 +212,6 @@ types (and values):
[endsect]
[#numeric_conversion_definitions_range]
[section Range and Precision]
Given a number set `N`, some of its elements are representable in a numeric type `T`.
@@ -318,8 +312,6 @@ while the higher the number of mantissa bits, the higher the precision.
[endsect]
[#numeric_conversion_definitions_roundoff]
[section Exact, Correctly Rounded and Out-Of-Range Representations]
Given an abstract value `V` and a type `T` with its corresponding range `[abt(l),abt(h)]`:
@@ -454,8 +446,6 @@ that is, the conversion is required to be correctly rounded.
[endsect]
[#numeric_conversion_definitions_subranged]
[section Subranged Conversion Direction, Subtype and Supertype]
Given a source type `S` and a destination type `T`, there is a
@@ -1,34 +1,30 @@
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<div class="section" lang="en">
<div class="section" title="bounds&lt;&gt; traits class">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.bounds___traits_class"></a><a href="bounds___traits_class.html" title="bounds&lt;&gt;
traits class">bounds&lt;&gt;
<a name="boost_numericconversion.bounds___traits_class"></a><a class="link" href="bounds___traits_class.html" title="bounds&lt;&gt; traits class">bounds&lt;&gt;
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</h2></div></div></div>
<div class="toc"><dl>
@@ -37,9 +33,9 @@
class bounds&lt;N&gt;</a></span></dt>
<dt><span class="section"><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples">Examples</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Introduction">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.bounds___traits_class.introduction"></a><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.introduction" title="Introduction">Introduction</a>
<a name="boost_numericconversion.bounds___traits_class.introduction"></a><a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.introduction" title="Introduction">Introduction</a>
</h3></div></div></div>
<p>
To determine the ranges of numeric types with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>
@@ -57,14 +53,12 @@
at compile time, so there is no runtime overhead.
</p>
</div>
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<div class="section" title="traits class bounds&lt;N&gt;">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.bounds___traits_class.traits_class_bounds_n_"></a><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_" title="traits
class bounds&lt;N&gt;">traits
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class bounds&lt;N&gt;</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">N</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">N</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">bounds</span>
<span class="special">{</span>
<span class="keyword">static</span> <span class="identifier">N</span> <span class="identifier">lowest</span> <span class="special">()</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">implementation_defined</span><span class="special">;</span> <span class="special">}</span>
@@ -73,8 +67,8 @@
<span class="special">};</span>
</pre>
<a name="boost_numericconversion.bounds___traits_class.traits_class_bounds_n_.members"></a><h5>
<a name="id2626217"></a>
<a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_.members">Members</a>
<a name="id565414"></a>
<a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.traits_class_bounds_n_.members">Members</a>
</h5>
<div class="blockquote"><blockquote class="blockquote">
<p>
@@ -117,15 +111,14 @@
denormalization, or returns 0 for integral types.
</p>
</div>
<div class="section" lang="en">
<div class="section" title="Examples">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.bounds___traits_class.examples"></a><a href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples" title="Examples">Examples</a>
<a name="boost_numericconversion.bounds___traits_class.examples"></a><a class="link" href="bounds___traits_class.html#boost_numericconversion.bounds___traits_class.examples" title="Examples">Examples</a>
</h3></div></div></div>
<p>
The following example demonstrates the use of <code class="computeroutput"><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special">&lt;&gt;</span></code> and the equivalent code using <code class="computeroutput"><span class="identifier">numeric_limits</span></code>:
</p>
<pre class="programlisting">
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">bounds</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">limits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
@@ -153,11 +146,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="type_requirements_and_user_defined_types_support.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../images/home.png" alt="Home"></a><a accesskey="n" href="conversion_traits___traits_class.html"><img src="../images/next.png" alt="Next"></a>
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@@ -1,61 +1,39 @@
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>conversion_traits&lt;&gt;
traits class</title>
<title>conversion_traits&lt;&gt; traits class</title>
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<div class="section" title="conversion_traits&lt;&gt; traits class">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.conversion_traits___traits_class"></a><a href="conversion_traits___traits_class.html" title="conversion_traits&lt;&gt;
traits class">conversion_traits&lt;&gt;
<a name="boost_numericconversion.conversion_traits___traits_class"></a><a class="link" href="conversion_traits___traits_class.html" title="conversion_traits&lt;&gt; traits class">conversion_traits&lt;&gt;
traits class</a>
</h2></div></div></div>
<div class="toc"><dl>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types">Types</a></span></dt>
<dd><dl>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum">enumeration
int_float_mixture_enum</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum">enumeration
sign_mixture_enum</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum">enumeration
udt_builtin_mixture_enum</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__">template
class int_float_mixture&lt;&gt;</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__">template
class sign_mixture&lt;&gt;</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__">template
class udt_builtin_mixture&lt;&gt;</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__">template
class is_subranged&lt;&gt;</a></span></dt>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__">template
class conversion_traits&lt;&gt;</a></span></dt>
</dl></dd>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.examples">Examples</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Types">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types" title="Types">Types</a>
<a name="boost_numericconversion.conversion_traits___traits_class.types"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types" title="Types">Types</a>
</h3></div></div></div>
<div class="toc"><dl>
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum">enumeration
@@ -75,16 +53,12 @@
<dt><span class="section"><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__">template
class conversion_traits&lt;&gt;</a></span></dt>
</dl></div>
<a name="numeric_conversion_traits_int_float_mixture_enum"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="enumeration int_float_mixture_enum">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum" title="enumeration
int_float_mixture_enum">enumeration
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum" title="enumeration int_float_mixture_enum">enumeration
int_float_mixture_enum</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">enum</span> <span class="identifier">int_float_mixture_enum</span>
<span class="special">{</span>
@@ -97,16 +71,12 @@
<span class="special">}</span> <span class="special">}</span> <span class="comment">// namespace boost::numeric
</span></pre>
</div>
<a name="numeric_conversion_traits_sign_mixture_enum"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="enumeration sign_mixture_enum">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum" title="enumeration
sign_mixture_enum">enumeration
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum" title="enumeration sign_mixture_enum">enumeration
sign_mixture_enum</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">enum</span> <span class="identifier">sign_mixture_enum</span>
<span class="special">{</span>
@@ -119,16 +89,12 @@
<span class="special">}</span> <span class="special">}</span> <span class="comment">// namespace boost::numeric
</span></pre>
</div>
<a name="numeric_conversion_traits_udt_builtin_mixture_enum"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="enumeration udt_builtin_mixture_enum">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum" title="enumeration
udt_builtin_mixture_enum">enumeration
<a name="boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum" title="enumeration udt_builtin_mixture_enum">enumeration
udt_builtin_mixture_enum</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">enum</span> <span class="identifier">udt_builtin_mixture_enum</span>
<span class="special">{</span>
@@ -141,16 +107,12 @@
<span class="special">}</span> <span class="special">}</span> <span class="comment">// namespace boost::numeric
</span></pre>
</div>
<a name="numeric_conversion_traits_class_int_float_mixture"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="template class int_float_mixture&lt;&gt;">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__" title="template
class int_float_mixture&lt;&gt;">template
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__" title="template class int_float_mixture&lt;&gt;">template
class int_float_mixture&lt;&gt;</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">int_float_mixture</span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">integral_c</span><span class="special">&lt;</span><span class="identifier">int_float_mixture_enum</span><span class="special">,</span> <span class="identifier">impl</span><span class="special">-</span><span class="identifier">def</span><span class="special">-</span><span class="identifier">value</span><span class="special">&gt;</span> <span class="special">{}</span> <span class="special">;</span>
@@ -159,24 +121,20 @@
</span></pre>
<p>
Classifying <code class="computeroutput"><span class="identifier">S</span></code> and <code class="computeroutput"><span class="identifier">T</span></code> as either integral or float, this
<a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's Integral
Constant</a> indicates the combination of these attributes.
<a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> indicates the combination of these attributes.
</p>
<p>
Its <code class="computeroutput"><span class="special">::</span><span class="identifier">value</span></code>
is of enumeration type <a href="conversion_traits___traits_class.html#numeric_conversion_traits_int_float_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">int_float_mixture_enum</span></code></a>
is of enumeration type <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_int_float_mixture_enum" title="enumeration int_float_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">int_float_mixture_enum</span></code></a>
</p>
</div>
<a name="numeric_conversion_traits_class_sign_mixture"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="template class sign_mixture&lt;&gt;">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__" title="template
class sign_mixture&lt;&gt;">template
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__" title="template class sign_mixture&lt;&gt;">template
class sign_mixture&lt;&gt;</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">sign_mixture</span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">integral_c</span><span class="special">&lt;</span><span class="identifier">sign_mixture_enum</span><span class="special">,</span> <span class="identifier">impl</span><span class="special">-</span><span class="identifier">def</span><span class="special">-</span><span class="identifier">value</span><span class="special">&gt;</span> <span class="special">{}</span> <span class="special">;</span>
@@ -185,24 +143,20 @@
</span></pre>
<p>
Classifying <code class="computeroutput"><span class="identifier">S</span></code> and <code class="computeroutput"><span class="identifier">T</span></code> as either signed or unsigned, this
<a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's Integral
Constant</a> indicates the combination of these attributes.
<a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> indicates the combination of these attributes.
</p>
<p>
Its <code class="computeroutput"><span class="special">::</span><span class="identifier">value</span></code>
is of enumeration type <a href="conversion_traits___traits_class.html#numeric_conversion_traits_sign_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">sign_mixture_enum</span></code></a>
is of enumeration type <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_sign_mixture_enum" title="enumeration sign_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">sign_mixture_enum</span></code></a>
</p>
</div>
<a name="numeric_conversion_traits_class_udt_builtin_mixture"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="template class udt_builtin_mixture&lt;&gt;">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__" title="template
class udt_builtin_mixture&lt;&gt;">template
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__" title="template class udt_builtin_mixture&lt;&gt;">template
class udt_builtin_mixture&lt;&gt;</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">udt_builtin_mixture</span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">integral_c</span><span class="special">&lt;</span><span class="identifier">udt_builtin__mixture_enum</span><span class="special">,</span> <span class="identifier">impl</span><span class="special">-</span><span class="identifier">def</span><span class="special">-</span><span class="identifier">value</span><span class="special">&gt;</span> <span class="special">{}</span> <span class="special">;</span>
@@ -211,24 +165,20 @@
</span></pre>
<p>
Classifying <code class="computeroutput"><span class="identifier">S</span></code> and <code class="computeroutput"><span class="identifier">T</span></code> as either user-defined or builtin,
this <a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's
this <a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> indicates the combination of these attributes.
</p>
<p>
Its <code class="computeroutput"><span class="special">::</span><span class="identifier">value</span></code>
is of enumeration type <a href="conversion_traits___traits_class.html#numeric_conversion_traits_udt_builtin_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">udt_builtin_mixture_enum</span></code></a>
is of enumeration type <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.enumeration_udt_builtin_mixture_enum" title="enumeration udt_builtin_mixture_enum"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">udt_builtin_mixture_enum</span></code></a>
</p>
</div>
<a name="numeric_conversion_traits_is_subranged"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="template class is_subranged&lt;&gt;">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__" title="template
class is_subranged&lt;&gt;">template
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__" title="template class is_subranged&lt;&gt;">template
class is_subranged&lt;&gt;</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">is_subranged</span> <span class="special">:</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">bool_</span><span class="special">&lt;</span><span class="identifier">impl</span><span class="special">-</span><span class="identifier">def</span><span class="special">-</span><span class="identifier">value</span><span class="special">&gt;</span> <span class="special">{}</span> <span class="special">;</span>
@@ -242,7 +192,7 @@
range.
</p>
<p>
It is a boolean <a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's
It is a boolean <a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> .
</p>
<p>
@@ -251,14 +201,12 @@
the source values are representable as Target type.
</p>
</div>
<div class="section" lang="en">
<div class="section" title="template class conversion_traits&lt;&gt;">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__" title="template
class conversion_traits&lt;&gt;">template
<a name="boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_conversion_traits__" title="template class conversion_traits&lt;&gt;">template
class conversion_traits&lt;&gt;</a>
</h4></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">conversion_traits</span>
@@ -285,11 +233,11 @@
direction: from a source type <code class="computeroutput"><span class="identifier">S</span></code>
to a target type <code class="computeroutput"><span class="identifier">T</span></code>. It
does not indicate the properties of a <span class="emphasis"><em>specific</em></span> conversion,
but of the conversion direction. See <a href="definitions.html#numeric_conversion_definitions_subranged">Definitions</a>
but of the conversion direction. See <a class="link" href="definitions.html#boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype" title="Subranged Conversion Direction, Subtype and Supertype">Definitions</a>
for details.
</p>
<p>
The traits class provides the following <a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's
The traits class provides the following <a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> \s of enumeration type. They express the combination
of certain attributes of the Source and Target types (thus they are call
mixture):
@@ -318,7 +266,7 @@
</td>
<td>
<p>
Same as given by the traits class <a href="conversion_traits___traits_class.html#numeric_conversion_traits_class_int_float_mixture">int_float_mixture</a>
Same as given by the traits class <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_int_float_mixture__" title="template class int_float_mixture&lt;&gt;">int_float_mixture</a>
</p>
</td>
</tr>
@@ -330,7 +278,7 @@
</td>
<td>
<p>
Same as given by the traits class <a href="conversion_traits___traits_class.html#numeric_conversion_traits_class_sign_mixture">sign_mixture</a>
Same as given by the traits class <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_sign_mixture__" title="template class sign_mixture&lt;&gt;">sign_mixture</a>
</p>
</td>
</tr>
@@ -342,16 +290,16 @@
</td>
<td>
<p>
Same as given by the traits class <a href="conversion_traits___traits_class.html#numeric_conversion_traits_class_udt_builtin_mixture">udt_builtin_mixture</a>
Same as given by the traits class <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_udt_builtin_mixture__" title="template class udt_builtin_mixture&lt;&gt;">udt_builtin_mixture</a>
</p>
</td>
</tr>
</tbody>
</table></div>
<p>
The traits class provides the following <a href="../../../../../mpl/refmanual/integral-constant.html" target="_top">MPL's
The traits class provides the following <a href="../../../../../mpl/doc/refmanual/integral-constant.html" target="_top">MPL's
Integral Constant</a> \s of boolean type which indicates indirectly
the relation between the Source and Target ranges (see <a href="definitions.html#numeric_conversion_definitions_range">Definitions</a>
the relation between the Source and Target ranges (see <a class="link" href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">Definitions</a>
for details).
</p>
<div class="informaltable"><table class="table">
@@ -378,7 +326,7 @@
</td>
<td>
<p>
Same as given by <a href="conversion_traits___traits_class.html#numeric_conversion_traits_is_subranged">is_subranged</a>
Same as given by <a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.types.template_class_is_subranged__" title="template class is_subranged&lt;&gt;">is_subranged</a>
</p>
</td>
</tr>
@@ -459,7 +407,7 @@
<span class="keyword">const</span><span class="special">&amp;</span></code>.
</p>
<p>
It represents the optimal argument type for the <a href="../index.html#numeric_conversion_converter">converter</a>
It represents the optimal argument type for the <a class="link" href="converter___function_object.html" title="converter&lt;&gt; function object">converter</a>
member functions.
</p>
<p>
@@ -480,7 +428,7 @@
This type is either target_type or target_type const&amp;
</p>
<p>
It represents the return type of the <a href="../index.html#numeric_conversion_converter">converter</a>
It represents the return type of the <a class="link" href="converter___function_object.html" title="converter&lt;&gt; function object">converter</a>
member functions.
</p>
<p>
@@ -520,12 +468,11 @@
</table></div>
</div>
</div>
<div class="section" lang="en">
<div class="section" title="Examples">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.conversion_traits___traits_class.examples"></a><a href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.examples" title="Examples">Examples</a>
<a name="boost_numericconversion.conversion_traits___traits_class.examples"></a><a class="link" href="conversion_traits___traits_class.html#boost_numericconversion.conversion_traits___traits_class.examples" title="Examples">Examples</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">cassert</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">cassert</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">typeinfo</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">conversion_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
@@ -555,11 +502,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="bounds___traits_class.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../images/home.png" alt="Home"></a><a accesskey="n" href="numeric_converter_policy_classes.html"><img src="../images/next.png" alt="Next"></a>
<a accesskey="p" href="bounds___traits_class.html"><img src="../../../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="numeric_converter_policy_classes.html"><img src="../../../../../../doc/html/images/next.png" alt="Next"></a>
</div>
</body>
</html>
@@ -1,33 +1,30 @@
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>converter&lt;&gt;
function object</title>
<title>converter&lt;&gt; function object</title>
<link rel="stylesheet" href="../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.70.1">
<link rel="start" href="../index.html" title="Chapter 1. Boost.NumericConversion">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../index.html" title="Chapter 1. Boost.NumericConversion">
<link rel="up" href="../index.html" title="Chapter 1. Boost.NumericConversion">
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<link rel="next" href="type_requirements_and_user_defined_types_support.html" title="Type
Requirements and User-defined-types support">
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</head>
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</div>
<div class="section" lang="en">
<div class="section" title="converter&lt;&gt; function object">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.converter___function_object"></a><a href="converter___function_object.html" title="converter&lt;&gt;
function object">converter&lt;&gt;
<a name="boost_numericconversion.converter___function_object"></a><a class="link" href="converter___function_object.html" title="converter&lt;&gt; function object">converter&lt;&gt;
function object</a>
</h2></div></div></div>
<div class="toc"><dl>
@@ -40,12 +37,11 @@
Checking Logic</a></span></dt>
<dt><span class="section"><a href="converter___function_object.html#boost_numericconversion.converter___function_object.examples">Examples</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Synopsis">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.converter___function_object.synopsis"></a><a href="converter___function_object.html#boost_numericconversion.converter___function_object.synopsis" title="Synopsis">Synopsis</a>
<a name="boost_numericconversion.converter___function_object.synopsis"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.synopsis" title="Synopsis">Synopsis</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span>
@@ -84,15 +80,14 @@
is a <a href="http://www.sgi.com/tech/stl/UnaryFunction.html" target="_top">Unary Function
Object</a> encapsulating the code to perform a numeric conversion with
the direction and properties specified by the Traits template parameter.
It can optionally take some <a href="../index.html#numeric_coversion_converter_policies">policies</a>
It can optionally take some <a class="link" href="numeric_converter_policy_classes.html" title="Numeric Converter Policy Classes">policies</a>
which can be used to customize its behavior. The <code class="computeroutput"><span class="identifier">Traits</span></code>
parameter is not a policy but the parameter that defines the conversion.
</p>
</div>
<div class="section" lang="en">
<div class="section" title="Template parameters">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.converter___function_object.template_parameters"></a><a href="converter___function_object.html#boost_numericconversion.converter___function_object.template_parameters" title="Template
parameters">Template
<a name="boost_numericconversion.converter___function_object.template_parameters"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.template_parameters" title="Template parameters">Template
parameters</a>
</h3></div></div></div>
<div class="informaltable"><table class="table">
@@ -119,7 +114,7 @@
</td>
<td>
<p>
The <a href="definitions.html#numeric_conversion_definitions_numeric_types">Numeric
The <a class="link" href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">Numeric
Type</a> which is the <span class="emphasis"><em>Target</em></span> of the conversion.
</p>
</td>
@@ -132,7 +127,7 @@
</td>
<td>
<p>
The <a href="definitions.html#numeric_conversion_definitions_numeric_types">Numeric
The <a class="link" href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">Numeric
Type</a> which is the <span class="emphasis"><em>Source</em></span> of the conversion.
</p>
</td>
@@ -145,7 +140,7 @@
</td>
<td>
<p>
This must be a conversion traits class with the interface of <a href="../index.html#numeric_conversion_traits"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">conversion_traits</span></code></a>
This must be a conversion traits class with the interface of <a class="link" href="conversion_traits___traits_class.html" title="conversion_traits&lt;&gt; traits class"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">conversion_traits</span></code></a>
</p>
</td>
</tr>
@@ -222,10 +217,9 @@
</tbody>
</table></div>
</div>
<div class="section" lang="en">
<div class="section" title="Member functions">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.converter___function_object.member_functions"></a><a href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions" title="Member
functions">Member
<a name="boost_numericconversion.converter___function_object.member_functions"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions" title="Member functions">Member
functions</a>
</h3></div></div></div>
<div class="blockquote"><blockquote class="blockquote">
@@ -254,8 +248,7 @@
The implementation of this function is actually built from the policies and
is basically as follows:
</p>
<pre class="programlisting">
<span class="identifier">result_type</span> <span class="identifier">converter</span><span class="special">&lt;&gt;::</span><span class="identifier">convert</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span>
<pre class="programlisting"><span class="identifier">result_type</span> <span class="identifier">converter</span><span class="special">&lt;&gt;::</span><span class="identifier">convert</span> <span class="special">(</span> <span class="identifier">argument_type</span> <span class="identifier">s</span> <span class="special">)</span>
<span class="special">{</span>
<span class="identifier">validate_range</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span> <span class="comment">// Implemented by the internal range checking logic
</span> <span class="comment">// (which also calls the OverflowHandler policy)
@@ -286,29 +279,29 @@
</p>
</blockquote></div>
<p>
This <a href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
static member function determines if the value <code class="computeroutput"><span class="identifier">s</span></code>
can be represented by the target type without overflow.
</p>
<p>
It does not determine if the conversion is <span class="emphasis"><em>exact</em></span>; that
is, it does not detect <span class="emphasis"><em>inexact</em></span> conversions, only <span class="emphasis"><em>out-of-range</em></span>
conversions (see the <a href="definitions.html#numeric_conversion_definitions_roundoff">Definitions</a>
conversions (see the <a class="link" href="definitions.html#boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations" title="Exact, Correctly Rounded and Out-Of-Range Representations">Definitions</a>
for further details).
</p>
<p>
The return value is of enum type <a href="numeric_converter_policy_classes.html#numeric_conversion_converter_policies_range_check_result"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">range_check_result</span></code></a>
The return value is of enum type <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result" title="enum range_check_result"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">range_check_result</span></code></a>
</p>
<p>
The actual code for the range checking logic is optimized for the combined
properties of the source and target types. For example, a non-subranged conversion
(i.e: <code class="computeroutput"><span class="keyword">int</span></code>-&gt;<code class="computeroutput"><span class="keyword">float</span></code>), requires no range checking, so <code class="computeroutput"><span class="identifier">out_of_range</span><span class="special">()</span></code>
returns <code class="computeroutput"><span class="identifier">cInRange</span></code> directly.
See the following <a href="converter___function_object.html#numeric_conversion_converter_range_checking_logic">table</a>
See the following <a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic" title="Range Checking Logic">table</a>
for more details.
</p>
<p>
If the user supplied a <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_user_range_checker">UserRangeChecker</a>
If the user supplied a <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a>
policy, is this policy which implements this function, so the implementation
is user defined, although it is expected to perform the same conceptual check
and return the appropriate result.
@@ -330,9 +323,9 @@
</p>
</blockquote></div>
<p>
This <a href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
static member function calls out_of_range(s), and passes the result to the
<a href="numeric_converter_policy_classes.html#numeric_conversion_policy_overflow_handler">OverflowHandler</a>
<a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy OverflowHandler">OverflowHandler</a>
policy class.
</p>
<p>
@@ -340,7 +333,7 @@
this is an empty inline function.
</p>
<p>
If the user supplied a <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_user_range_checker">UserRangeChecker</a>
If the user supplied a <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a>
policy, is this policy which implements this function, so the implementation
is user defined, although it is expected to perform the same action as the
default. In particular, it is expected to pass the result of the check to
@@ -362,11 +355,11 @@
</p>
</blockquote></div>
<p>
This <a href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
static member function performs the actual conversion.
</p>
<p>
This function is externally supplied by the <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_raw_converter">RawConverter</a>
This function is externally supplied by the <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">RawConverter</a>
policy class.
</p>
<p>
@@ -385,14 +378,14 @@
</p>
</blockquote></div>
<p>
This <a href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
This <a class="link" href="converter___function_object.html#numeric_conversion_converter_internal">internal</a>
static member function, which is <span class="underline">only used</span>
for <code class="computeroutput"><span class="keyword">float</span></code> to <code class="computeroutput"><span class="keyword">int</span></code>
conversions, returns an <span class="emphasis"><em>integer</em></span> value of <span class="emphasis"><em><span class="underline">floating-point type</span></em></span> according to some
rounding direction.
</p>
<p>
This function is externally supplied by the <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_float_to_int_rounder">Float2IntRounder</a>
This function is externally supplied by the <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy Float2IntRounder">Float2IntRounder</a>
policy class which encapsulates the specific rounding mode.
</p>
<p>
@@ -401,8 +394,8 @@
<a name="numeric_conversion_converter_internal"></a><p>
</p>
<a name="boost_numericconversion.converter___function_object.member_functions.internal_member_functions"></a><h5>
<a name="id2623952"></a>
<a href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions.internal_member_functions">Internal
<a name="id563268"></a>
<a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.member_functions.internal_member_functions">Internal
Member Functions</a>
</h5>
<p>
@@ -411,12 +404,9 @@
called separately for specific needs.
</p>
</div>
<a name="numeric_conversion_converter_range_checking_logic"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Range Checking Logic">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.converter___function_object.range_checking_logic"></a><a href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic" title="Range
Checking Logic">Range
<a name="boost_numericconversion.converter___function_object.range_checking_logic"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.range_checking_logic" title="Range Checking Logic">Range
Checking Logic</a>
</h3></div></div></div>
<p>
@@ -463,12 +453,11 @@ float_to_float |--&gt; subranged |--&gt; ( s &gt;= S(LowestT) ) &amp;&amp; (
</code>
</pre>
</div>
<div class="section" lang="en">
<div class="section" title="Examples">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.converter___function_object.examples"></a><a href="converter___function_object.html#boost_numericconversion.converter___function_object.examples" title="Examples">Examples</a>
<a name="boost_numericconversion.converter___function_object.examples"></a><a class="link" href="converter___function_object.html#boost_numericconversion.converter___function_object.examples" title="Examples">Examples</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">cassert</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">cassert</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">converter</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> <span class="special">{</span>
@@ -497,11 +486,15 @@ float_to_float |--&gt; subranged |--&gt; ( s &gt;= S(LowestT) ) &amp;&amp; (
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
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+154 -177
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@@ -3,29 +3,28 @@
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</div>
<div class="section" lang="en">
<div class="section" title="Definitions">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.definitions"></a><a href="definitions.html" title="Definitions">Definitions</a>
<a name="boost_numericconversion.definitions"></a><a class="link" href="definitions.html" title="Definitions">Definitions</a>
</h2></div></div></div>
<div class="toc"><dl>
<dt><span class="section"><a href="definitions.html#boost_numericconversion.definitions.introduction">Introduction</a></span></dt>
@@ -44,15 +43,16 @@
<dt><span class="section"><a href="definitions.html#boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype">Subranged
Conversion Direction, Subtype and Supertype</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Introduction">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.introduction"></a><a href="definitions.html#boost_numericconversion.definitions.introduction" title="Introduction">Introduction</a>
<a name="boost_numericconversion.definitions.introduction"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.introduction" title="Introduction">Introduction</a>
</h3></div></div></div>
<p>
This section provides definitions of terms used in the Numeric Conversion
library.
</p>
<div class="sidebar">
<p class="title"><b></b></p>
<p>
<span class="bold"><strong>Notation</strong></span> <span class="underline">underlined
text</span> denotes terms defined in the C++ standard.
@@ -63,10 +63,9 @@
</p>
</div>
</div>
<div class="section" lang="en">
<div class="section" title="Types and Values">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.types_and_values"></a><a href="definitions.html#boost_numericconversion.definitions.types_and_values" title="Types
and Values">Types
<a name="boost_numericconversion.definitions.types_and_values"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.types_and_values" title="Types and Values">Types
and Values</a>
</h3></div></div></div>
<p>
@@ -161,12 +160,9 @@
of this document.
</p>
</div>
<a name="numeric_conversion_cpp_arithmetic_types"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="C++ Arithmetic Types">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.c___arithmetic_types"></a><a href="definitions.html#boost_numericconversion.definitions.c___arithmetic_types" title="C++
Arithmetic Types">C++
<a name="boost_numericconversion.definitions.c___arithmetic_types"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.c___arithmetic_types" title="C++ Arithmetic Types">C++
Arithmetic Types</a>
</h3></div></div></div>
<p>
@@ -179,35 +175,42 @@
<dl>
<dt><span class="term"><span class="underline">signed integer
types</span> (§3.9.1/2):</span></dt>
<dd>
<code class="computeroutput"><span class="special">{</span><span class="keyword">signed</span>
<span class="keyword">char</span><span class="special">,</span>
<span class="keyword">signed</span> <span class="keyword">short</span>
<span class="keyword">int</span><span class="special">,</span> <span class="keyword">signed</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">signed</span> <span class="keyword">long</span> <span class="keyword">int</span><span class="special">}</span></code> Can be used to represent general integer
numbers (both negative and positive).
</dd>
<dd><p>
<code class="computeroutput"><span class="special">{</span><span class="keyword">signed</span>
<span class="keyword">char</span><span class="special">,</span>
<span class="keyword">signed</span> <span class="keyword">short</span>
<span class="keyword">int</span><span class="special">,</span>
<span class="keyword">signed</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">signed</span> <span class="keyword">long</span> <span class="keyword">int</span><span class="special">}</span></code> Can be used to represent general integer
numbers (both negative and positive).
</p></dd>
<dt><span class="term"><span class="underline">unsigned integer
types</span> (§3.9.1/3):</span></dt>
<dd>
<code class="computeroutput"><span class="special">{</span><span class="keyword">unsigned</span>
<span class="keyword">char</span><span class="special">,</span>
<span class="keyword">unsigned</span> <span class="keyword">short</span>
<span class="keyword">int</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">int</span><span class="special">}</span></code> Can be used to represent positive integer
numbers with modulo-arithmetic.
</dd>
<dd><p>
<code class="computeroutput"><span class="special">{</span><span class="keyword">unsigned</span>
<span class="keyword">char</span><span class="special">,</span>
<span class="keyword">unsigned</span> <span class="keyword">short</span>
<span class="keyword">int</span><span class="special">,</span>
<span class="keyword">unsigned</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">int</span><span class="special">}</span></code> Can be used to represent positive integer
numbers with modulo-arithmetic.
</p></dd>
<dt><span class="term"><span class="underline">floating-point
types</span> (§3.9.1/8):</span></dt>
<dd>
<code class="computeroutput"><span class="special">{</span><span class="keyword">float</span><span class="special">,</span><span class="keyword">double</span><span class="special">,</span><span class="keyword">long</span> <span class="keyword">double</span><span class="special">}</span></code> Can be used to represent real numbers.
</dd>
<dd><p>
<code class="computeroutput"><span class="special">{</span><span class="keyword">float</span><span class="special">,</span><span class="keyword">double</span><span class="special">,</span><span class="keyword">long</span> <span class="keyword">double</span><span class="special">}</span></code>
Can be used to represent real numbers.
</p></dd>
<dt><span class="term"><span class="underline">integral or
integer types</span> (§3.9.1/7):</span></dt>
<dd><code class="computeroutput"><span class="special">{{</span><span class="keyword">signed</span>
<span class="identifier">integers</span><span class="special">},{</span><span class="keyword">unsigned</span> <span class="identifier">integers</span><span class="special">},</span> <span class="keyword">bool</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">and</span> <span class="keyword">wchar_t</span><span class="special">}</span></code></dd>
<dd><p>
<code class="computeroutput"><span class="special">{{</span><span class="keyword">signed</span>
<span class="identifier">integers</span><span class="special">},{</span><span class="keyword">unsigned</span> <span class="identifier">integers</span><span class="special">},</span> <span class="keyword">bool</span><span class="special">,</span> <span class="keyword">char</span> <span class="keyword">and</span> <span class="keyword">wchar_t</span><span class="special">}</span></code>
</p></dd>
<dt><span class="term"><span class="underline">arithmetic
types</span> (§3.9.1/8):</span></dt>
<dd><code class="computeroutput"><span class="special">{{</span><span class="identifier">integer</span>
<span class="identifier">types</span><span class="special">},{</span><span class="identifier">floating</span> <span class="identifier">types</span><span class="special">}}</span></code></dd>
<dd><p>
<code class="computeroutput"><span class="special">{{</span><span class="identifier">integer</span>
<span class="identifier">types</span><span class="special">},{</span><span class="identifier">floating</span> <span class="identifier">types</span><span class="special">}}</span></code>
</p></dd>
</dl>
</div>
<p>
@@ -219,8 +222,7 @@
or <code class="computeroutput"><span class="keyword">long</span></code>) are required to have
the same value representation, that is:
</p>
<pre class="programlisting">
<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">-</span><span class="number">3</span> <span class="special">;</span> <span class="comment">// suppose value representation is: 10011 (sign bit + 4 magnitude bits)
<pre class="programlisting"> <span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">-</span><span class="number">3</span> <span class="special">;</span> <span class="comment">// suppose value representation is: 10011 (sign bit + 4 magnitude bits)
</span><span class="keyword">unsigned</span> <span class="keyword">int</span> <span class="identifier">u</span> <span class="special">=</span> <span class="identifier">i</span> <span class="special">;</span> <span class="comment">// u is required to have the same 10011 as its value representation.
</span></pre>
<p>
@@ -232,43 +234,32 @@
Another consequence of this is that the range for signed X is always a smaller
subset of the range of unsigned X, as required by §3.9.1/3.
</p>
<div class="note"><table border="0" summary="Note">
<div class="note" title="Note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../images/note.png"></td>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/html/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top">
<p>
</p>
Always remember that unsigned types, unlike signed types, have modulo-arithmetic;
that is, they do not overflow. This means that:
</p>
<p>
Always remember that unsigned types, unlike signed types, have modulo-arithmetic;
that is, they do not overflow. This means that:
</p>
<p>
</p>
<p>
<span class="bold"><strong>-</strong></span> Always be extra careful when mixing
signed/unsigned types
</p>
<p>
</p>
<p>
<span class="bold"><strong>-</strong></span> Use unsigned types only when you need
modulo arithmetic or very very large numbers. Don't use unsigned types
just because you intend to deal with positive values only (you can do
this with signed types as well).
</p>
<span class="bold"><strong>-</strong></span> Always be extra careful when mixing
signed/unsigned types
</p>
<p>
<span class="bold"><strong>-</strong></span> Use unsigned types only when you need
modulo arithmetic or very very large numbers. Don't use unsigned types
just because you intend to deal with positive values only (you can do this
with signed types as well).
</p>
</td></tr>
</table></div>
</div>
<a name="numeric_conversion_definitions_numeric_types"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Numeric Types">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.numeric_types"></a><a href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric
Types">Numeric
<a name="boost_numericconversion.definitions.numeric_types"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">Numeric
Types</a>
</h3></div></div></div>
<p>
@@ -284,26 +275,26 @@
<p>
A type is <span class="bold"><strong>numeric</strong></span> if:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
It is an arithmetic type, or,
</li>
<li>
<li class="listitem">
It is a user-defined type which
<div class="itemizedlist"><ul type="circle">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="circle">
<li class="listitem">
Represents numeric abstract values (i.e. numbers).
</li>
<li>
<li class="listitem">
Can be converted (either implicitly or explicitly) to/from at least
one arithmetic type.
</li>
<li>
Has <a href="definitions.html#numeric_conversion_definitions_range">range</a>
(possibly unbounded) and <a href="definitions.html#numeric_conversion_definitions_range">precision</a>
<li class="listitem">
Has <a class="link" href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">range</a>
(possibly unbounded) and <a class="link" href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">precision</a>
(possibly dynamic or unlimited).
</li>
<li>
<li class="listitem">
Provides an specialization of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span></code>.
</li>
</ul></div>
@@ -347,8 +338,7 @@
The following examples clarify the differences between arithmetic and numeric
types (and values):
</p>
<pre class="programlisting">
<span class="comment">// A numeric type which is not an arithmetic type (is user-defined)
<pre class="programlisting"><span class="comment">// A numeric type which is not an arithmetic type (is user-defined)
</span><span class="comment">// and which is intended to represent integer numbers (i.e., an 'integer' numeric type)
</span><span class="keyword">class</span> <span class="identifier">MyInt</span>
<span class="special">{</span>
@@ -373,12 +363,9 @@
</span><span class="identifier">MyInt</span> <span class="identifier">i</span><span class="special">(</span><span class="number">1234</span><span class="special">);</span>
</pre>
</div>
<a name="numeric_conversion_definitions_range"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Range and Precision">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.range_and_precision"></a><a href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range
and Precision">Range
<a name="boost_numericconversion.definitions.range_and_precision"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">Range
and Precision</a>
</h3></div></div></div>
<p>
@@ -440,8 +427,7 @@
of numeric values (of type <code class="computeroutput"><span class="identifier">T</span></code>)
of the form:
</p>
<pre class="programlisting">
<span class="identifier">REP</span><span class="special">(</span><span class="identifier">T</span><span class="special">)={</span><span class="identifier">l</span><span class="special">,</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">l</span><span class="special">)),...,</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">h</span><span class="special">)),</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">h</span><span class="special">),</span><span class="identifier">h</span><span class="special">}</span>
<pre class="programlisting"><span class="identifier">REP</span><span class="special">(</span><span class="identifier">T</span><span class="special">)={</span><span class="identifier">l</span><span class="special">,</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">l</span><span class="special">),</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">next</span><span class="special">(</span><span class="identifier">l</span><span class="special">)),...,</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">h</span><span class="special">)),</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">h</span><span class="special">),</span><span class="identifier">h</span><span class="special">}</span>
</pre>
<p>
where <code class="computeroutput"><span class="identifier">l</span></code> and <code class="computeroutput"><span class="identifier">h</span></code> are respectively the lowest and highest
@@ -496,12 +482,12 @@
<p>
This definition was chosen because:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<span class="bold"><strong>(a)</strong></span> The discrete set of numeric values
is already given by the numeric set.
</li>
<li>
<li class="listitem">
<span class="bold"><strong>(b)</strong></span> Abstract intervals are easier to compare
and overlap since only boundary values need to be considered.
</li>
@@ -537,12 +523,9 @@
of mantissa bits, the higher the precision.
</p>
</div>
<a name="numeric_conversion_definitions_roundoff"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Exact, Correctly Rounded and Out-Of-Range Representations">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations"></a><a href="definitions.html#boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations" title="Exact,
Correctly Rounded and Out-Of-Range Representations">Exact,
<a name="boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.exact__correctly_rounded_and_out_of_range_representations" title="Exact, Correctly Rounded and Out-Of-Range Representations">Exact,
Correctly Rounded and Out-Of-Range Representations</a>
</h3></div></div></div>
<p>
@@ -559,13 +542,13 @@
or, equivalently, it's representation in the type <code class="computeroutput"><span class="identifier">T</span></code>
is <span class="bold"><strong>out of range</strong></span>, or <span class="bold"><strong>overflows</strong></span>.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
If <code class="computeroutput"><span class="identifier">V</span> <span class="special">&lt;</span>
<span class="identifier">abt</span><span class="special">(</span><span class="identifier">l</span><span class="special">)</span></code>, the
<span class="bold"><strong>overflow is negative</strong></span>.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="identifier">V</span> <span class="special">&gt;</span>
<span class="identifier">abt</span><span class="special">(</span><span class="identifier">h</span><span class="special">)</span></code>, the
<span class="bold"><strong>overflow is positive</strong></span>.
@@ -600,13 +583,13 @@
the roundoff error corresponds to the representation operation and not to
the numeric value itself (i.e. numeric values do not have any error themselves)
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
If the roundoff is 0, the representation is <span class="bold"><strong>exact</strong></span>,
and <code class="computeroutput"><span class="identifier">V</span></code> is exactly representable
in the type <code class="computeroutput"><span class="identifier">T</span></code>.
</li>
<li>
<li class="listitem">
If the roundoff is not 0, the representation is <span class="bold"><strong>inexact</strong></span>,
and <code class="computeroutput"><span class="identifier">V</span></code> is inexactly representable
in the type <code class="computeroutput"><span class="identifier">T</span></code>.
@@ -640,24 +623,24 @@
<p>
The following examples summarize the given definitions. Consider:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
A numeric type <code class="computeroutput"><span class="identifier">Int</span></code> representing
integer numbers with a <span class="emphasis"><em>numeric set</em></span>: <code class="computeroutput"><span class="special">{-</span><span class="number">2</span><span class="special">,-</span><span class="number">1</span><span class="special">,</span><span class="number">0</span><span class="special">,</span><span class="number">1</span><span class="special">,</span><span class="number">2</span><span class="special">}</span></code> and <span class="emphasis"><em>range</em></span>:
<code class="computeroutput"><span class="special">[-</span><span class="number">2</span><span class="special">,</span><span class="number">2</span><span class="special">]</span></code>
</li>
<li>
<li class="listitem">
A numeric type <code class="computeroutput"><span class="identifier">Cardinal</span></code>
representing integer numbers with a <span class="emphasis"><em>numeric set</em></span>:
<code class="computeroutput"><span class="special">{</span><span class="number">0</span><span class="special">,</span><span class="number">1</span><span class="special">,</span><span class="number">2</span><span class="special">,</span><span class="number">3</span><span class="special">,</span><span class="number">4</span><span class="special">,</span><span class="number">5</span><span class="special">,</span><span class="number">6</span><span class="special">,</span><span class="number">7</span><span class="special">,</span><span class="number">8</span><span class="special">,</span><span class="number">9</span><span class="special">}</span></code> and <span class="emphasis"><em>range</em></span>: <code class="computeroutput"><span class="special">[</span><span class="number">0</span><span class="special">,</span><span class="number">9</span><span class="special">]</span></code> (no modulo-arithmetic
here)
</li>
<li>
<li class="listitem">
A numeric type <code class="computeroutput"><span class="identifier">Real</span></code> representing
real numbers with a <span class="emphasis"><em>numeric set</em></span>: <code class="computeroutput"><span class="special">{-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.5</span><span class="special">,-</span><span class="number">1.0</span><span class="special">,-</span><span class="number">0.5</span><span class="special">,-</span><span class="number">0.0</span><span class="special">,+</span><span class="number">0.0</span><span class="special">,+</span><span class="number">0.5</span><span class="special">,+</span><span class="number">1.0</span><span class="special">,+</span><span class="number">1.5</span><span class="special">,+</span><span class="number">2.0</span><span class="special">}</span></code> and
<span class="emphasis"><em>range</em></span>: <code class="computeroutput"><span class="special">[-</span><span class="number">2.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">]</span></code>
</li>
<li>
<li class="listitem">
A numeric type <code class="computeroutput"><span class="identifier">Whole</span></code> representing
real numbers with a <span class="emphasis"><em>numeric set</em></span>: <code class="computeroutput"><span class="special">{-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.0</span><span class="special">,</span><span class="number">0.0</span><span class="special">,+</span><span class="number">1.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">}</span></code> and <span class="emphasis"><em>range</em></span>: <code class="computeroutput"><span class="special">[-</span><span class="number">2.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">]</span></code>
</li>
@@ -667,35 +650,35 @@
and <code class="computeroutput"><span class="identifier">Whole</span></code> both represent
real numbers, have the same range, but different precision.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
The integer number <code class="computeroutput"><span class="number">1</span></code> (an abstract
value) can be exactly represented in any of these types.
</li>
<li>
<li class="listitem">
The integer number <code class="computeroutput"><span class="special">-</span><span class="number">1</span></code>
can be exactly represented in <code class="computeroutput"><span class="identifier">Int</span></code>,
<code class="computeroutput"><span class="identifier">Real</span></code> and <code class="computeroutput"><span class="identifier">Whole</span></code>, but cannot be represented in
<code class="computeroutput"><span class="identifier">Cardinal</span></code>, yielding negative
overflow.
</li>
<li>
<li class="listitem">
The real number <code class="computeroutput"><span class="number">1.5</span></code> can be
exactly represented in <code class="computeroutput"><span class="identifier">Real</span></code>,
and inexactly represented in the other types.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="number">1.5</span></code> is represented as either
<code class="computeroutput"><span class="number">1</span></code> or <code class="computeroutput"><span class="number">2</span></code>
in any of the types (except <code class="computeroutput"><span class="identifier">Real</span></code>),
the representation is correctly rounded.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="number">0.5</span></code> is represented as <code class="computeroutput"><span class="special">+</span><span class="number">1.5</span></code> in the
type <code class="computeroutput"><span class="identifier">Real</span></code>, it is incorrectly
rounded.
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="special">(-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.5</span><span class="special">)</span></code>
are the <code class="computeroutput"><span class="identifier">Real</span></code> adjacents
of any real number in the interval <code class="computeroutput"><span class="special">[-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.5</span><span class="special">]</span></code>, yet there are no <code class="computeroutput"><span class="identifier">Real</span></code>
@@ -706,10 +689,9 @@
</li>
</ul></div>
</div>
<div class="section" lang="en">
<div class="section" title="Standard (numeric) Conversions">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.standard__numeric__conversions"></a><a href="definitions.html#boost_numericconversion.definitions.standard__numeric__conversions" title="Standard
(numeric) Conversions">Standard
<a name="boost_numericconversion.definitions.standard__numeric__conversions"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.standard__numeric__conversions" title="Standard (numeric) Conversions">Standard
(numeric) Conversions</a>
</h3></div></div></div>
<p>
@@ -739,8 +721,8 @@
<p>
Integer to integer conversions are always defined:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
If <code class="computeroutput"><span class="identifier">T</span></code> is unsigned, the abstract
value which is effectively represented is not <code class="computeroutput"><span class="identifier">N</span></code>
but <code class="computeroutput"><span class="identifier">M</span><span class="special">=[</span>
@@ -750,7 +732,7 @@
<code class="computeroutput"><span class="identifier">h</span></code> is the highest unsigned
typed value of type <code class="computeroutput"><span class="identifier">T</span></code>.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="identifier">T</span></code> is signed and <code class="computeroutput"><span class="identifier">N</span></code> is not directly representable, the
result <code class="computeroutput"><span class="identifier">t</span></code> is <span class="underline">implementation-defined</span>,
which means that the C++ implementation is required to produce a value
@@ -763,13 +745,13 @@
is representable; if it is not, the conversion has <span class="underline">undefined
behavior</span>.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
If <code class="computeroutput"><span class="identifier">N</span></code> is exactly representable,
<code class="computeroutput"><span class="identifier">t</span></code> is required to be the
exact representation.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="identifier">N</span></code> is inexactly representable,
<code class="computeroutput"><span class="identifier">t</span></code> is required to be one
of the two adjacents, with an implementation-defined choice of rounding
@@ -782,7 +764,7 @@
<code class="computeroutput"><span class="identifier">trunc</span><span class="special">()</span></code>
is to truncate: i.e. to remove the fractional part, if any.
</p>
<div class="itemizedlist"><ul type="disc"><li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
If <code class="computeroutput"><span class="identifier">M</span></code> is not representable
in <code class="computeroutput"><span class="identifier">T</span></code>, the conversion has
<span class="underline">undefined behavior</span> (unless <code class="computeroutput"><span class="identifier">T</span></code> is <code class="computeroutput"><span class="keyword">bool</span></code>,
@@ -791,13 +773,13 @@
<p>
Integer to Floating conversions are always defined.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
If <code class="computeroutput"><span class="identifier">N</span></code> is exactly representable,
<code class="computeroutput"><span class="identifier">t</span></code> is required to be the
exact representation.
</li>
<li>
<li class="listitem">
If <code class="computeroutput"><span class="identifier">N</span></code> is inexactly representable,
<code class="computeroutput"><span class="identifier">t</span></code> is required to be one
of the two adjacents, with an implementation-defined choice of rounding
@@ -805,12 +787,9 @@
</li>
</ul></div>
</div>
<a name="numeric_conversion_definitions_subranged"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Subranged Conversion Direction, Subtype and Supertype">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype"></a><a href="definitions.html#boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype" title="Subranged
Conversion Direction, Subtype and Supertype">Subranged
<a name="boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype"></a><a class="link" href="definitions.html#boost_numericconversion.definitions.subranged_conversion_direction__subtype_and_supertype" title="Subranged Conversion Direction, Subtype and Supertype">Subranged
Conversion Direction, Subtype and Supertype</a>
</h3></div></div></div>
<p>
@@ -856,15 +835,15 @@
<p>
Given the following numeric types all representing real numbers:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<code class="computeroutput"><span class="identifier">X</span></code> with numeric set <code class="computeroutput"><span class="special">{-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.0</span><span class="special">,</span><span class="number">0.0</span><span class="special">,+</span><span class="number">1.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">}</span></code> and
range <code class="computeroutput"><span class="special">[-</span><span class="number">2.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">]</span></code>
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="identifier">Y</span></code> with numeric set <code class="computeroutput"><span class="special">{-</span><span class="number">2.0</span><span class="special">,-</span><span class="number">1.5</span><span class="special">,-</span><span class="number">1.0</span><span class="special">,-</span><span class="number">0.5</span><span class="special">,</span><span class="number">0.0</span><span class="special">,+</span><span class="number">0.5</span><span class="special">,+</span><span class="number">1.0</span><span class="special">,+</span><span class="number">1.5</span><span class="special">,+</span><span class="number">2.0</span><span class="special">}</span></code> and range <code class="computeroutput"><span class="special">[-</span><span class="number">2.0</span><span class="special">,+</span><span class="number">2.0</span><span class="special">]</span></code>
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="identifier">Z</span></code> with numeric set <code class="computeroutput"><span class="special">{-</span><span class="number">1.0</span><span class="special">,</span><span class="number">0.0</span><span class="special">,+</span><span class="number">1.0</span><span class="special">}</span></code> and range <code class="computeroutput"><span class="special">[-</span><span class="number">1.0</span><span class="special">,+</span><span class="number">1.0</span><span class="special">]</span></code>
</li>
</ul></div>
@@ -875,37 +854,31 @@
<p class="title"><b></b></p>
<dl>
<dt><span class="term">(a) X-&gt;Y:</span></dt>
<dd>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">&amp;</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span> <span class="special">==</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span></code>, then
<code class="computeroutput"><span class="identifier">X</span><span class="special">-&gt;</span><span class="identifier">Y</span></code> is not subranged. Thus, all values
of type <code class="computeroutput"><span class="identifier">X</span></code> are representable
in the type <code class="computeroutput"><span class="identifier">Y</span></code>.
</dd>
<dd><p>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">&amp;</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span></code>,
then <code class="computeroutput"><span class="identifier">X</span><span class="special">-&gt;</span><span class="identifier">Y</span></code> is not subranged. Thus, all values
of type <code class="computeroutput"><span class="identifier">X</span></code> are representable
in the type <code class="computeroutput"><span class="identifier">Y</span></code>.
</p></dd>
<dt><span class="term">(b) Y-&gt;X:</span></dt>
<dd>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span> <span class="special">&amp;</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">==</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span></code>, then
<code class="computeroutput"><span class="identifier">Y</span><span class="special">-&gt;</span><span class="identifier">X</span></code> is not subranged. Thus, all values
of type <code class="computeroutput"><span class="identifier">Y</span></code> are representable
in the type <code class="computeroutput"><span class="identifier">X</span></code>, but in this
case, some values are <span class="emphasis"><em>inexactly</em></span> representable (all
the halves). (note: it is to permit this case that a range is an interval
of abstract values and not an interval of typed values)
</dd>
<dd><p>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span> <span class="special">&amp;</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">Y</span><span class="special">)</span></code>,
then <code class="computeroutput"><span class="identifier">Y</span><span class="special">-&gt;</span><span class="identifier">X</span></code> is not subranged. Thus, all values
of type <code class="computeroutput"><span class="identifier">Y</span></code> are representable
in the type <code class="computeroutput"><span class="identifier">X</span></code>, but in
this case, some values are <span class="emphasis"><em>inexactly</em></span> representable
(all the halves). (note: it is to permit this case that a range is an
interval of abstract values and not an interval of typed values)
</p></dd>
<dt><span class="term">(b) X-&gt;Z:</span></dt>
<dd>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">&amp;</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">Z</span><span class="special">)</span> <span class="special">!=</span>
<span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span></code>, then
<code class="computeroutput"><span class="identifier">X</span><span class="special">-&gt;</span><span class="identifier">Z</span></code> is subranged. Thus, some values of
type <code class="computeroutput"><span class="identifier">X</span></code> are not representable
in the type <code class="computeroutput"><span class="identifier">Z</span></code>, they fall
out of range <code class="computeroutput"><span class="special">(-</span><span class="number">2.0</span>
<span class="keyword">and</span> <span class="special">+</span><span class="number">2.0</span><span class="special">)</span></code>.
</dd>
<dd><p>
<code class="computeroutput"><span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span> <span class="special">&amp;</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">Z</span><span class="special">)</span> <span class="special">!=</span> <span class="identifier">R</span><span class="special">(</span><span class="identifier">X</span><span class="special">)</span></code>,
then <code class="computeroutput"><span class="identifier">X</span><span class="special">-&gt;</span><span class="identifier">Z</span></code> is subranged. Thus, some values of
type <code class="computeroutput"><span class="identifier">X</span></code> are not representable
in the type <code class="computeroutput"><span class="identifier">Z</span></code>, they fall
out of range <code class="computeroutput"><span class="special">(-</span><span class="number">2.0</span>
<span class="keyword">and</span> <span class="special">+</span><span class="number">2.0</span><span class="special">)</span></code>.
</p></dd>
</dl>
</div>
<p>
@@ -944,12 +917,12 @@
If <code class="computeroutput"><span class="identifier">FLT_MAX</span> <span class="special">&lt;</span>
<span class="identifier">DBL_MAX</span></code>:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<code class="computeroutput"><span class="keyword">double</span><span class="special">-&gt;</span><span class="keyword">float</span></code> is subranged and <code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="keyword">double</span></code>,
<code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="keyword">float</span></code>.
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="keyword">float</span><span class="special">-&gt;</span><span class="keyword">double</span></code> is not subranged and <code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="keyword">double</span></code>, <code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="keyword">float</span></code>.
</li>
</ul></div>
@@ -975,12 +948,12 @@
<span class="special">&gt;</span> <span class="identifier">INT_MAX</span></code>
(§3.9/3), so:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
'int-&gt;unsigned' is subranged (negative values fall out of range) and
<code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="keyword">int</span></code>, <code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="keyword">unsigned</span></code>.
</li>
<li>
<li class="listitem">
'unsigned-&gt;int' is <span class="emphasis"><em>also</em></span> subranged (high positive
values fall out of range) and <code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="keyword">unsigned</span></code>,
<code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="keyword">int</span></code>.
@@ -1007,11 +980,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
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@@ -1,34 +1,30 @@
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<div class="section" lang="en">
<div class="section" title="Improved numeric_cast&lt;&gt;">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.improved_numeric_cast__"></a><a href="improved_numeric_cast__.html" title="Improved
numeric_cast&lt;&gt;">Improved
<a name="boost_numericconversion.improved_numeric_cast__"></a><a class="link" href="improved_numeric_cast__.html" title="Improved numeric_cast&lt;&gt;">Improved
numeric_cast&lt;&gt;</a>
</h2></div></div></div>
<div class="toc"><dl>
@@ -36,29 +32,29 @@
<dt><span class="section"><a href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast">numeric_cast</a></span></dt>
<dt><span class="section"><a href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.examples">Examples</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Introduction">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.improved_numeric_cast__.introduction"></a><a href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.introduction" title="Introduction">Introduction</a>
<a name="boost_numericconversion.improved_numeric_cast__.introduction"></a><a class="link" href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.introduction" title="Introduction">Introduction</a>
</h3></div></div></div>
<p>
The lack of preservation of range makes conversions between numeric types
error prone. This is true for both implicit conversions and explicit conversions
(through <code class="computeroutput"><span class="keyword">static_cast</span></code>). <a href="improved_numeric_cast__.html#numeric_conversion_numeric_cast"><code class="computeroutput"><span class="identifier">numeric_cast</span></code></a>
detects loss of range when a numeric type is converted, and throws an exception
if the range cannot be preserved.
(through <code class="computeroutput"><span class="keyword">static_cast</span></code>). <a class="link" href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast" title="numeric_cast"><code class="computeroutput"><span class="identifier">numeric_cast</span></code></a> detects loss of range
when a numeric type is converted, and throws an exception if the range cannot
be preserved.
</p>
<p>
There are several situations where conversions are unsafe:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
Conversions from an integral type with a wider range than the target integral
type.
</li>
<li>
<li class="listitem">
Conversions from unsigned to signed (and vice versa) integral types.
</li>
<li>
<li class="listitem">
Conversions from floating point types to integral types.
</li>
</ul></div>
@@ -80,14 +76,11 @@
values of the source type, there will be no runtime overhead.
</p>
</div>
<a name="numeric_conversion_numeric_cast"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="numeric_cast">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.improved_numeric_cast__.numeric_cast"></a><a href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast" title="numeric_cast">numeric_cast</a>
<a name="boost_numericconversion.improved_numeric_cast__.numeric_cast"></a><a class="link" href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.numeric_cast" title="numeric_cast">numeric_cast</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Target</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Source</span><span class="special">&gt;</span> <span class="keyword">inline</span>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Target</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Source</span><span class="special">&gt;</span> <span class="keyword">inline</span>
<span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">converter</span><span class="special">&lt;</span><span class="identifier">Target</span><span class="special">,</span><span class="identifier">Source</span><span class="special">&gt;::</span><span class="identifier">result_type</span>
<span class="identifier">numeric_cast</span> <span class="special">(</span> <span class="identifier">Source</span> <span class="identifier">arg</span> <span class="special">)</span>
<span class="special">{</span>
@@ -97,29 +90,28 @@
<p>
<code class="computeroutput"><span class="identifier">numeric_cast</span></code> returns the
result of converting a value of type Source to a value of type Target. If
out-of-range is detected, an exception is thrown (see <a href="numeric_converter_policy_classes.html#numeric_conversion_bad_numeric_cast">bad_numeric_cast</a>,
<a href="numeric_converter_policy_classes.html#numeric_conversion_negative_overflow">negative_overflow</a>
and <a href="numeric_converter_policy_classes.html#numeric_conversion_possitive_overflow">positive_overflow</a>
out-of-range is detected, an exception is thrown (see <a class="link" href="numeric_converter_policy_classes.html#numeric_conversion_bad_numeric_cast">bad_numeric_cast</a>,
<a class="link" href="numeric_converter_policy_classes.html#numeric_conversion_negative_overflow">negative_overflow</a>
and <a class="link" href="numeric_converter_policy_classes.html#numeric_conversion_possitive_overflow">positive_overflow</a>
).
</p>
</div>
<div class="section" lang="en">
<div class="section" title="Examples">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.improved_numeric_cast__.examples"></a><a href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.examples" title="Examples">Examples</a>
<a name="boost_numericconversion.improved_numeric_cast__.examples"></a><a class="link" href="improved_numeric_cast__.html#boost_numericconversion.improved_numeric_cast__.examples" title="Examples">Examples</a>
</h3></div></div></div>
<p>
The following example performs some typical conversions between numeric types:
</p>
<div class="orderedlist"><ol type="1">
<li>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
include &lt;boost/numeric/conversion/cast.hpp&gt;
</li>
<li>
<li class="listitem">
include &lt;iostream&gt;
</li>
</ol></div>
<pre class="programlisting">
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric_cast</span><span class="special">;</span>
@@ -174,11 +166,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
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@@ -1,34 +1,30 @@
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.numeric_converter_policy_classes"></a><a href="numeric_converter_policy_classes.html" title="Numeric
Converter Policy Classes">Numeric
<a name="boost_numericconversion.numeric_converter_policy_classes"></a><a class="link" href="numeric_converter_policy_classes.html" title="Numeric Converter Policy Classes">Numeric
Converter Policy Classes</a>
</h2></div></div></div>
<div class="toc"><dl>
@@ -43,16 +39,12 @@
<dt><span class="section"><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker">Policy
UserRangeChecker</a></span></dt>
</dl></div>
<a name="numeric_conversion_converter_policies_range_check_result"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="enum range_check_result">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result"></a><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result" title="enum
range_check_result">enum
<a name="boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result"></a><a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.enum_range_check_result" title="enum range_check_result">enum
range_check_result</a>
</h3></div></div></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">enum</span> <span class="identifier">range_check_result</span>
<span class="special">{</span>
@@ -67,12 +59,9 @@
Defines the values returned by <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">converter</span><span class="special">&lt;&gt;::</span><span class="identifier">out_of_range</span><span class="special">()</span></code>
</p>
</div>
<a name="numeric_conversion_policy_overflow_handler"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Policy OverflowHandler">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler"></a><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy
OverflowHandler">Policy
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler"></a><a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy OverflowHandler">Policy
OverflowHandler</a>
</h3></div></div></div>
<p>
@@ -85,8 +74,7 @@
<p>
It must have the following interface (it does not has to be a template class):
</p>
<pre class="programlisting">
<span class="keyword">struct</span> <span class="identifier">YourOverflowHandlerPolicy</span>
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">YourOverflowHandlerPolicy</span>
<span class="special">{</span>
<span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()</span> <span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">range_check_result</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// throw bad_cast or derived
</span><span class="special">}</span> <span class="special">;</span>
@@ -97,8 +85,7 @@
<p>
These are the two overflow handler classes provided by the library:
</p>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">struct</span> <span class="identifier">def_overflow_handler</span>
<span class="special">{</span>
@@ -121,11 +108,10 @@
</pre>
<p>
And these are the Exception Classes thrown by the default overflow handler
<a href="numeric_converter_policy_classes.html#numeric_conversion_policy_overflow_handler_important_note">(see
<a class="link" href="numeric_converter_policy_classes.html#numeric_conversion_policy_overflow_handler_important_note">(see
IMPORTANT note)</a>
</p>
<a name="numeric_conversion_bad_numeric_cast"></a><a name="numeric_conversion_negative_overflow"></a><a name="numeric_conversion_possitive_overflow"></a><pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<a name="numeric_conversion_bad_numeric_cast"></a><a name="numeric_conversion_negative_overflow"></a><a name="numeric_conversion_possitive_overflow"></a><pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">class</span> <span class="identifier">bad_numeric_cast</span> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">bad_cast</span>
@@ -163,38 +149,29 @@
</pre>
<a name="numeric_conversion_policy_overflow_handler_important_note"></a><p>
</p>
<div class="important"><table border="0" summary="Important">
<div class="important" title="Important"><table border="0" summary="Important">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../images/important.png"></td>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../../../doc/html/images/important.png"></td>
<th align="left">Important</th>
</tr>
<tr><td align="left" valign="top">
<p>
</p>
<p>
<span class="bold"><strong>RELEASE NOTE for 1.33</strong></span> Previous to boost
version 1.33, the exception class <code class="computeroutput"><span class="identifier">bad_numeric_cast</span></code>
was named <code class="computeroutput"><span class="identifier">bad_numeric_conversion</span></code>.
However, in 1.33, the old function <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> from <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
was completly replaced by the new <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> in <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
(and <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code> is including <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
now). That old function which existed in boost for quite some time used
the <code class="computeroutput"><span class="identifier">bad_numeric_cast</span></code>
as its exception type so I decided to avoid backward compatibility problems
by adopting it (guessing that the user base for the old code is wider
than for the new code).
</p>
<p>
</p>
</td></tr>
<tr><td align="left" valign="top"><p>
<span class="bold"><strong>RELEASE NOTE for 1.33</strong></span> Previous to boost
version 1.33, the exception class <code class="computeroutput"><span class="identifier">bad_numeric_cast</span></code>
was named <code class="computeroutput"><span class="identifier">bad_numeric_conversion</span></code>.
However, in 1.33, the old function <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> from <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
was completly replaced by the new <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> in <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
(and <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code> is including <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">cast</span><span class="special">.</span><span class="identifier">hpp</span></code>
now). That old function which existed in boost for quite some time used
the <code class="computeroutput"><span class="identifier">bad_numeric_cast</span></code> as
its exception type so I decided to avoid backward compatibility problems
by adopting it (guessing that the user base for the old code is wider than
for the new code).
</p></td></tr>
</table></div>
</div>
<a name="numeric_conversion_policy_float_to_int_rounder"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Policy Float2IntRounder">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder"></a><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy
Float2IntRounder">Policy
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder"></a><a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy Float2IntRounder">Policy
Float2IntRounder</a>
</h3></div></div></div>
<p>
@@ -207,8 +184,7 @@
<p>
The policy must have the following interface:
</p>
<pre class="programlisting">
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">YourFloat2IntRounderPolicy</span>
<span class="special">{</span>
<span class="keyword">typedef</span> <span class="identifier">S</span> <span class="identifier">source_type</span> <span class="special">;</span>
@@ -224,25 +200,18 @@
These are the rounder classes provided by the library (only the specific
parts are shown, see the general policy form above)
</p>
<div class="note"><table border="0" summary="Note">
<div class="note" title="Note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../images/note.png"></td>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/html/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top">
<p>
</p>
<p>
These classes are not intended to be general purpose rounding functions
but specific policies for <code class="computeroutput"><span class="identifier">converter</span><span class="special">&lt;&gt;</span></code>. This is why they are not function
objects.
</p>
<p>
</p>
</td></tr>
<tr><td align="left" valign="top"><p>
These classes are not intended to be general purpose rounding functions
but specific policies for <code class="computeroutput"><span class="identifier">converter</span><span class="special">&lt;&gt;</span></code>. This is why they are not function
objects.
</p></td></tr>
</table></div>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">&gt;</span>
@@ -299,8 +268,8 @@
<span class="special">}</span> <span class="special">}</span> <span class="comment">// namespace numeric, namespace boost
</span></pre>
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder.math_functions_used_by_the_rounder_policies"></a><h5>
<a name="id2633882"></a>
<a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder.math_functions_used_by_the_rounder_policies">Math
<a name="id572764"></a>
<a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder.math_functions_used_by_the_rounder_policies">Math
Functions used by the rounder policies</a>
</h5>
<p>
@@ -318,16 +287,13 @@
This technique allows the default rounder policies to be used directly with
user defined types. The user only requires that suitable overloads of <code class="computeroutput"><span class="identifier">floor</span><span class="special">()</span></code>
and <code class="computeroutput"><span class="identifier">ceil</span><span class="special">()</span></code>
be visible. See also <a href="../index.html#numeric_conversion_requirements">User
be visible. See also <a class="link" href="type_requirements_and_user_defined_types_support.html" title="Type Requirements and User-defined-types support">User
Defined Numeric Types</a> support.
</p>
</div>
<a name="numeric_conversion_policy_raw_converter"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Policy RawConverter">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter"></a><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy
RawConverter">Policy
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter"></a><a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">Policy
RawConverter</a>
</h3></div></div></div>
<p>
@@ -339,8 +305,7 @@
<p>
The policy must have the following interface:
</p>
<pre class="programlisting">
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">YourRawConverterPolicy</span>
<span class="special">{</span>
<span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">result_type</span> <span class="identifier">result_type</span> <span class="special">;</span>
@@ -357,8 +322,7 @@
<p>
This is the only raw converter policy class provided by the library:
</p>
<pre class="programlisting">
<span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">numeric</span> <span class="special">{</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">raw_numeric_converter</span>
@@ -375,12 +339,9 @@
<span class="special">}</span> <span class="special">}</span>
</pre>
</div>
<a name="numeric_conversion_policy_user_range_checker"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Policy UserRangeChecker">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker"></a><a href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy
UserRangeChecker">Policy
<a name="boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker"></a><a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">Policy
UserRangeChecker</a>
</h3></div></div></div>
<p>
@@ -394,8 +355,7 @@
<p>
The policy must have the following interface:
</p>
<pre class="programlisting">
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">&gt;</span>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">Traits</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">YourRangeCheckerPolicy</span>
<span class="special">{</span>
<span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Traits</span><span class="special">::</span><span class="identifier">argument_type</span> <span class="identifier">argument_type</span> <span class="special">;</span>
@@ -422,11 +382,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="conversion_traits___traits_class.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../images/home.png" alt="Home"></a><a accesskey="n" href="improved_numeric_cast__.html"><img src="../images/next.png" alt="Next"></a>
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</div>
</body>
</html>
@@ -1,34 +1,30 @@
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Type
Requirements and User-defined-types support</title>
<title>Type Requirements and User-defined-types support</title>
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</div>
<div class="section" lang="en">
<div class="section" title="Type Requirements and User-defined-types support">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support"></a><a href="type_requirements_and_user_defined_types_support.html" title="Type
Requirements and User-defined-types support">Type
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support"></a><a class="link" href="type_requirements_and_user_defined_types_support.html" title="Type Requirements and User-defined-types support">Type
Requirements and User-defined-types support</a>
</h2></div></div></div>
<div class="toc"><dl>
@@ -39,10 +35,9 @@
<dt><span class="section"><a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies">Special
Policies</a></span></dt>
</dl></div>
<div class="section" lang="en">
<div class="section" title="Type Requirements">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.type_requirements"></a><a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.type_requirements" title="Type
Requirements">Type
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.type_requirements"></a><a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.type_requirements" title="Type Requirements">Type
Requirements</a>
</h3></div></div></div>
<p>
@@ -60,8 +55,7 @@
policies uses unqualified calls to functions <code class="computeroutput"><span class="identifier">floor</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">ceil</span><span class="special">()</span></code>; but the standard functions are introduced
in scope by a using directive:
</p>
<pre class="programlisting">
<span class="keyword">using</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">floor</span> <span class="special">;</span> <span class="keyword">return</span> <span class="identifier">floor</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span>
<pre class="programlisting"><span class="keyword">using</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">floor</span> <span class="special">;</span> <span class="keyword">return</span> <span class="identifier">floor</span><span class="special">(</span><span class="identifier">s</span><span class="special">);</span>
</pre>
<p>
Therefore, for builtin arithmetic types, the std functions will be used.
@@ -79,48 +73,47 @@
user defined types require a visible <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;</span></code> in order to use the <code class="computeroutput"><span class="identifier">Trunc</span><span class="special">&lt;&gt;</span></code> policy (the default).
</p>
</div>
<div class="section" lang="en">
<div class="section" title="UDT's special semantics">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics"></a><a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics" title="UDT's
special semantics">UDT's
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics"></a><a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics" title="UDT's special semantics">UDT's
special semantics</a>
</h3></div></div></div>
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.conversion_traits"></a><h5>
<a name="id2625220"></a>
<a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.conversion_traits">Conversion
<a name="id564459"></a>
<a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.conversion_traits">Conversion
Traits</a>
</h5>
<p>
If a User Defined Type is involved in a conversion, it is <span class="emphasis"><em>assumed</em></span>
that the UDT has <a href="definitions.html#numeric_conversion_definitions_range">wider
that the UDT has <a class="link" href="definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">wider
range</a> than any built-in type, and consequently the values of some
<code class="computeroutput"><span class="identifier">converter_traits</span><span class="special">&lt;&gt;</span></code>
members are hardwired regardless of the reality. The following table summarizes
this:
</p>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<code class="computeroutput"><span class="identifier">Target</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>built-in</em></span><div class="itemizedlist"><ul type="circle">
<li><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">false</span></code></li>
<li><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
<li><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>built-in</em></span><div class="itemizedlist"><ul class="itemizedlist" type="circle">
<li class="listitem"><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">false</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
</ul></div>
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="identifier">Target</span><span class="special">=</span></code><span class="emphasis"><em>built-in</em></span>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span><div class="itemizedlist"><ul type="circle">
<li><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">true</span></code></li>
<li><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
<li><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span><div class="itemizedlist"><ul class="itemizedlist" type="circle">
<li class="listitem"><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">true</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
</ul></div>
</li>
<li>
<li class="listitem">
<code class="computeroutput"><span class="identifier">Target</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span><div class="itemizedlist"><ul type="circle">
<li><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">false</span></code></li>
<li><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
<li><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
and <code class="computeroutput"><span class="identifier">Source</span><span class="special">=</span></code><span class="emphasis"><em>UDT</em></span><div class="itemizedlist"><ul class="itemizedlist" type="circle">
<li class="listitem"><code class="computeroutput"><span class="identifier">subranged</span><span class="special">=</span><span class="keyword">false</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">supertype</span><span class="special">=</span><span class="identifier">Target</span></code></li>
<li class="listitem"><code class="computeroutput"><span class="identifier">subtype</span><span class="special">=</span><span class="identifier">Source</span></code></li>
</ul></div>
</li>
</ul></div>
@@ -130,8 +123,8 @@
above.
</p>
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.range_checking"></a><h5>
<a name="id2625640"></a>
<a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.range_checking">Range
<a name="id564867"></a>
<a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.udt_s_special_semantics.range_checking">Range
Checking</a>
</h5>
<p>
@@ -141,16 +134,13 @@
Target or Source are not built-in types, the bundled range checking of the
<code class="computeroutput"><span class="identifier">converter</span><span class="special">&lt;&gt;</span></code>
function object is automatically disabled. However, it is possible to supply
a user-defined range-checker. See <a href="type_requirements_and_user_defined_types_support.html#numeric_conversion_requirements_hooks">Special
a user-defined range-checker. See <a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies" title="Special Policies">Special
Policies</a>
</p>
</div>
<a name="numeric_conversion_requirements_hooks"></a><p>
</p>
<div class="section" lang="en">
<div class="section" title="Special Policies">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies"></a><a href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies" title="Special
Policies">Special
<a name="boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies"></a><a class="link" href="type_requirements_and_user_defined_types_support.html#boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies" title="Special Policies">Special
Policies</a>
</h3></div></div></div>
<p>
@@ -166,7 +156,7 @@
<p>
However, this internal logic is disabled when either type is User Defined.
In this case, the user can specify an <span class="emphasis"><em>external</em></span> range
checking policy which will be used in place of the internal code. See <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_user_range_checker">UserRangeChecker</a>
checking policy which will be used in place of the internal code. See <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a>
policy for details.
</p>
<p>
@@ -176,18 +166,22 @@
<p>
However, if the a UDT is involved, the <code class="computeroutput"><span class="keyword">static_cast</span></code>
might not work. In this case, the user can implement and pass a different
raw converter policy. See <a href="numeric_converter_policy_classes.html#numeric_conversion_policy_raw_converter">RawConverter</a>
raw converter policy. See <a class="link" href="numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">RawConverter</a>
policy for details
</p>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
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<div class="chapter" title="Chapter 1. Boost.NumericConversion">
<div class="titlepage"><div>
<div><h2 class="title">
<a name="numeric_conversion"></a>Chapter 1. Boost.NumericConversion</h2></div>
@@ -26,8 +26,8 @@
<span class="firstname">Fernando Luis</span> <span class="surname">Cacciola Carballal</span>
</h3></div></div>
<div><p class="copyright">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</p></div>
<div><div class="legalnotice">
<a name="id2604797"></a><p>
<div><div class="legalnotice" title="Legal Notice">
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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</p>
@@ -117,71 +117,61 @@
<dt><span class="section"><a href="numeric_conversion/bibliography.html">Bibliography</a></span></dt>
</dl>
</div>
<div class="section" lang="en">
<div class="section" title="Overview">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="numeric_conversion.overview"></a><a href="index.html#numeric_conversion.overview" title="Overview">Overview</a>
<a name="numeric_conversion.overview"></a><a class="link" href="index.html#numeric_conversion.overview" title="Overview">Overview</a>
</h2></div></div></div>
<p>
The Boost Numeric Conversion library is a collection of tools to describe and
perform conversions between values of different <a href="boost_numericconversion/definitions.html#numeric_conversion_definitions_numeric_types">numeric
perform conversions between values of different <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">numeric
types</a>.
</p>
<p>
The library includes a special alternative for a subset of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special">&lt;&gt;</span></code>, the <a href="index.html#numeric_conversion_bounds">bounds&lt;&gt;</a>
traits class, which provides a consistent way to obtain the <a href="boost_numericconversion/definitions.html#numeric_conversion_definitions_range">boundary</a>
values for the <a href="boost_numericconversion/definitions.html#numeric_conversion_definitions_range">range</a>
The library includes a special alternative for a subset of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">numeric_limits</span><span class="special">&lt;&gt;</span></code>, the <a class="link" href="boost_numericconversion/bounds___traits_class.html" title="bounds&lt;&gt; traits class">bounds&lt;&gt;</a>
traits class, which provides a consistent way to obtain the <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">boundary</a>
values for the <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.range_and_precision" title="Range and Precision">range</a>
of a numeric type.
</p>
<p>
It also includes a set of <a href="index.html#numeric_conversion_traits">trait classes</a>
which describes the compile-time properties of a conversion from a source to
a target numeric type. Both <a href="boost_numericconversion/definitions.html#numeric_conversion_cpp_arithmetic_types">arithmetic</a>
and <a href="boost_numericconversion/definitions.html#numeric_conversion_definitions_numeric_types">user-defined
It also includes a set of <a class="link" href="boost_numericconversion/conversion_traits___traits_class.html" title="conversion_traits&lt;&gt; traits class">trait
classes</a> which describes the compile-time properties of a conversion
from a source to a target numeric type. Both <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.c___arithmetic_types" title="C++ Arithmetic Types">arithmetic</a>
and <a class="link" href="boost_numericconversion/definitions.html#boost_numericconversion.definitions.numeric_types" title="Numeric Types">user-defined
numeric types</a> can be used.
</p>
<p>
A policy-based <a href="index.html#numeric_conversion_converter">converter</a>
A policy-based <a class="link" href="boost_numericconversion/converter___function_object.html" title="converter&lt;&gt; function object">converter</a>
object which uses <code class="computeroutput"><span class="identifier">conversion_traits</span></code>
to select an optimized implementation is supplied. Such implementation uses
an optimal range checking code suitable for the source/target combination.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
The converter's out-of-range behavior can be customized via an <a href="boost_numericconversion/numeric_converter_policy_classes.html#numeric_conversion_policy_overflow_handler">OverflowHandler</a>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
The converter's out-of-range behavior can be customized via an <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_overflowhandler" title="Policy OverflowHandler">OverflowHandler</a>
policy.
</li>
<li>
<li class="listitem">
For floating-point to integral conversions, the rounding mode can be selected
via the <a href="boost_numericconversion/numeric_converter_policy_classes.html#numeric_conversion_policy_float_to_int_rounder">Float2IntRounder</a>
via the <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_float2introunder" title="Policy Float2IntRounder">Float2IntRounder</a>
policy.
</li>
<li>
<li class="listitem">
A custom low-level conversion routine (for UDTs for instance) can be passed
via a <a href="boost_numericconversion/numeric_converter_policy_classes.html#numeric_conversion_policy_raw_converter">RawConverter</a>
via a <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter" title="Policy RawConverter">RawConverter</a>
policy.
</li>
<li>
The optimized automatic range-checking logic can be overridden via a <a href="boost_numericconversion/numeric_converter_policy_classes.html#numeric_conversion_policy_user_range_checker">UserRangeChecker</a>
<li class="listitem">
The optimized automatic range-checking logic can be overridden via a <a class="link" href="boost_numericconversion/numeric_converter_policy_classes.html#boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker" title="Policy UserRangeChecker">UserRangeChecker</a>
policy.
</li>
</ul></div>
</div>
<a name="numeric_conversion_converter"></a><p>
</p>
<a name="numeric_conversion_requirements"></a><p>
</p>
<a name="numeric_conversion_bounds"></a><p>
</p>
<a name="numeric_conversion_traits"></a><p>
</p>
<a name="numeric_coversion_converter_policies"></a><p>
</p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"><small><p>Last revised: June 04, 2007 at 03:08:57 GMT</p></small></td>
<td align="right"><small></small></td>
<td align="left"><p><small>Last revised: November 20, 2009 at 09:59:43 GMT</small></p></td>
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</h2></div></div></div>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
Standard Documents:
<div class="orderedlist"><ol type="1">
<li>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
ISO/IEC 14882:98 (C++98 Standard)
</li>
<li>
<li class="listitem">
ISO/IEC 9899:1999 (C99 Standard)
</li>
<li>
<li class="listitem">
ISO/IEC 10967-1 (Language Independent Arithmetic (LIA), Part I, 1994)
</li>
<li>
<li class="listitem">
ISO/IEC 2382-1:1993 (Information Technology - Vocabulary - Part I: Fundamental
Terms)
</li>
<li>
<li class="listitem">
ANSI/IEEE 754-1985 [and IEC 60559:1989] (Binary floating-point)
</li>
<li>
<li class="listitem">
ANSI/IEEE 854-1988 (Radix Independent floating-point)
</li>
<li>
<li class="listitem">
ANSI X3/TR-1-82 (Dictionary for Information Processing Systems)
</li>
<li>
<li class="listitem">
ISO/IEC JTC1/SC22/WG14/N753 C9X Revision Proposal: LIA-1 Binding: Rationale
</li>
</ol></div>
</li>
<li>
<li class="listitem">
Papers:
<div class="orderedlist"><ol type="1">
<li>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
David Goldberg What Every Computer Scientist Should Know About Floating-Point
Arithmetic
</li>
<li>
<li class="listitem">
Prof. William Kahan papers on floating-point.
</li>
</ol></div>
@@ -73,11 +72,15 @@
</div>
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<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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@@ -1,62 +1,59 @@
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="numeric_conversion.history_and_acknowledgments"></a><a href="history_and_acknowledgments.html" title="History
and Acknowledgments">History
<a name="numeric_conversion.history_and_acknowledgments"></a><a class="link" href="history_and_acknowledgments.html" title="History and Acknowledgments">History
and Acknowledgments</a>
</h2></div></div></div>
<a name="numeric_conversion.history_and_acknowledgments.pre_formal_review"></a><h4>
<a name="id2636340"></a>
<a href="history_and_acknowledgments.html#numeric_conversion.history_and_acknowledgments.pre_formal_review">Pre-formal
<a name="id575108"></a>
<a class="link" href="history_and_acknowledgments.html#numeric_conversion.history_and_acknowledgments.pre_formal_review">Pre-formal
review</a>
</h4>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
Kevlin Henney, with help from David Abrahams and Beman Dawes, originally
contributed the previous version of <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> which already presented the idea
of a runtime range check.
</li>
<li>
<li class="listitem">
Later, Eric Ford, Kevin Lynch and the author spotted some genericity problems
with that <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code>
which prevented it from being used in a generic layer of math functions.
</li>
<li>
<li class="listitem">
An improved <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> which properly handled all combinations
of arithmetic types was presented.
</li>
<li>
<li class="listitem">
David Abrahams and Beman Dawes acknowledged the need of an improved version
of <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code>
and supported the submission as originally laid out. Daryl Walker and Darin
Adler made some important comments and proposed fixes to the original submission.
</li>
<li>
<li class="listitem">
Special thanks go to Björn Karlsoon who helped the author considerably.
Having found the problems with <code class="computeroutput"><span class="identifier">numeric_cast</span><span class="special">&lt;&gt;</span></code> himself, he revised very carefully
the original submission and spot a subtle bug in the range checking implementation.
@@ -67,16 +64,16 @@
</li>
</ul></div>
<a name="numeric_conversion.history_and_acknowledgments.post_formal_review"></a><h4>
<a name="id2636492"></a>
<a href="history_and_acknowledgments.html#numeric_conversion.history_and_acknowledgments.post_formal_review">Post-formal
<a name="id575242"></a>
<a class="link" href="history_and_acknowledgments.html#numeric_conversion.history_and_acknowledgments.post_formal_review">Post-formal
review</a>
</h4>
<div class="itemizedlist"><ul type="disc">
<li>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
Guillaume Melquiond spoted some documentation and code issues, particularly
about rounding conversions.
</li>
<li>
<li class="listitem">
The following people contributed an important review of the design, documentation
and c ode: Kevin Lynch, Thorsten Ottosen, Paul Bristow, Daryle Walker, Jhon
Torjo, Eric Ford, Gennadiy Rozental.
@@ -85,11 +82,15 @@
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><small>Copyright © 2004 -2007 Fernando Luis Cacciola Carballal</small></td>
<td align="right"><div class="copyright-footer">Copyright © 2004 -2007 Fernando Luis Cacciola Carballal<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
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<TITLE>Boost Numeric Conversion Library - Index</TITLE>
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<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
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<H3><A HREF="../../../../index.htm"><IMG HEIGHT="86" WIDTH="277"
ALT="C++ Boost" SRC="../../../../boost.png" BORDER="0"></A></H3> </TH>
<TH VALIGN="top">
<H1 ALIGN="center">Boost Numeric Conversion Library</H1> </TH>
</TR>
</TABLE>
<HR>
<table border="0" cellpadding="0" width="100%">
<tr>
<td width="50%" valign="top"><font size="4">This Document</font><br><br>
&nbsp;&nbsp;&nbsp; <a href="#Overview">Overview</a><br>
&nbsp;&nbsp;&nbsp; <a href="#Ack">History and Acknowledgments</a><br>
&nbsp;&nbsp;&nbsp; <a href="#Ref">Bibliography</a><br>
</td>
<td width="50%"><font size="4">Other Documents</font><br><br>
&nbsp;&nbsp;&nbsp; <A HREF="definitions.html">Definitions</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="converter.html"><code>converter&lt;&gt;</code> function object</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="requirements.html">Type Requirements and User-defined-types support</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="bounds.html"><code>bounds&lt;&gt;</code> traits class</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="conversion_traits.html"><code>conversion_traits&lt;&gt;</code> traits class</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="converter_policies.html">Numeric Converter Policy Classes</A><br>
&nbsp;&nbsp;&nbsp; <A HREF="numeric_cast.html">Improved numeric_cast&lt;&gt;</A><br>
</td>
</tr>
</table>
<hr>
<H2><A NAME="Overview"></A>Overview</H2>
<P>The Boost Numeric Conversion library is a collection of tools to describe and perform
conversions between values of different <a href="definitions.html#numtypes">numeric types</a>.</p>
<p>The library includes a special alternative for a subset of <code>std::numeric_limits&lt;&gt;</code>,
the <A HREF="bounds.html"><code>bounds&lt;&gt;</code></A> traits class, which provides
a consistent way to obtain the <a href="definitions.html#range">boundary</a> values for the
<a href="definitions.html#range">range</a> of a numeric type.</p>
<p>It also includes a set of <A HREF="conversion_traits.html">trait classes</A> which
describes the compile-time properties of a conversion from a source to a target
numeric type. Both <a href="definitions.html#stdtypes">arithmetic</a> and <a href="definitions.html#numtypes">user-defined
numeric types</a> can be used.</p>
<p>A policy-based <A HREF="converter.html">converter</A> object which uses <code>conversion_traits</code>
to select an optimized implementation is supplied.
Such implementation uses an optimal range checking code suitable for the source/target combination.<br>
The converter's out-of-range behavior can be customized via an <A HREF="converter_policies.html#oh">OverflowHandler</A>
policy.<br>
For floating-point to integral conversions, the rounding mode can be selected via
the <A HREF="converter_policies.html#f2i">Float2IntRounder</A> policy.<br>
A custom low-level conversion routine (for UDTs for instance) can be passed
via a <A HREF="converter_policies.html#rawc">RawConverter</A> policy.<br>
The optimized automatic range-checking logic can be overridden via a <A HREF="converter_policies.html#rc">UserRangeChecker</A>
policy.</p>
<hr>
<H2><A NAME="Ack"></A>History and Acknowledgments</H2>
<p>Pre-formal review:</p>
<blockquote>
<p>Kevlin Henney, with help from David Abrahams and Beman Dawes, originally contributed
the previous version of numeric_cast&lt;&gt; which already presented the idea of a runtime range check.<br>
Later, Eric Ford, Kevin Lynch and the author spotted some genericity problems
with that numeric_cast&lt;&gt; which prevented it from being used in a generic
layer of math functions.<br>
An improved numeric_cast&lt;&gt; which properly handled all combinations of arithmetic types was presented.<br>
David Abrahams and Beman Dawes acknowledged the need of an improved version
of numeric_cast&lt;&gt; and supported the submission as originally laid out.
Daryl Walker and Darin Adler made some important comments and proposed fixes
to the original submission.</p>
<p>Special thanks go to Björn Karlsoon who helped the author considerably. Having
found the problems with numeric_cast&lt;&gt; himself, he revised very carefully
the original submission and spot a subtle bug in the range checking implementation.
He also wrote part of this documentation and proof-read and corrected other
parts. And most importantly: the features now presented here in this library
evolved from the original submission as a result of the useful private communications
between Björn and the author.</p>
</blockquote>
<p>Post-formal review:</p>
<p>Guillaume Melquiond spoted some documentation and code issues, particularly about rounding conversions.<br>
The following people contributed an important review of the design, documentation and code: Kevin Lynch, Thorsten Ottosen, Paul Bristow,
Daryle Walker, Jhon Torjo, Eric Ford, Gennadiy Rozental.
</p>
<hr>
<H2><A NAME="Ref"></A>Bibliography</H2>
<ul>
<li>Standard Documents:
<ol>
<li>ISO/IEC 14882:98 (C++98 Standard)</li>
<li>ISO/IEC 9899:1999 (C99 Standard)</li>
<li>ISO/IEC 10967-1 (Language Independent Arithmetic (LIA), Part I, 1994)</li>
<li>ISO/IEC 2382-1:1993 (Information Technology - Vocabulary - Part I: Fundamental Terms)</li>
<li>ANSI/IEEE 754-1985 [and IEC 60559:1989] (Binary floating-point)</li>
<li>ANSI/IEEE 854-1988 (Radix Independent floating-point)</li>
<li>ANSI X3/TR-1-82 (Dictionary for Information Processing Systems)</li>
<li><a href="http://anubis.dkuug.dk/JTC1/SC22/WG14/www/docs/n753.htm">ISO/IEC JTC1/SC22/WG14/N753</a> C9X Revision Proposal: LIA-1 Binding: Rationale</li>
</ol>
</li>
<li>Papers:
<ol>
<li>David Goldberg <A href="http://citeseer.ist.psu.edu/goldberg91what.html">
What Every Computer Scientist Should Know About Floating-Point Arithmetic</A></li>
<li><A href="http://www.cs.berkeley.edu/~wkahan/">Prof. William Kahan</A> papers on floating-point.</li>
</ol>
</li>
</ul>
<HR>
<P>Revised 23 June 2004</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</body>
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<HTML>
<HEAD>
<LINK REL="stylesheet" TYPE="text/css" HREF="../../../../boost.css">
<TITLE>Boost Numeric Conversion Library - numeric_cast</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
SUMMARY="header">
<TR>
<TH VALIGN="top" WIDTH="300">
<H3><A HREF="../../../../index.htm"><IMG HEIGHT="86" WIDTH="277"
ALT="C++ Boost" SRC="../../../../boost.png" BORDER="0"></A></H3> </TH>
<TH VALIGN="top">
<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1><A HREF="http://www.boost.org">Header </A><A
HREF="../../../../boost/numeric/conversion/cast.hpp">boost/numeric/conversion/cast.hpp</A></H1> </TH>
</TR>
</TABLE><HR>
<H2>Contents</H2>
<UL>
<LI><A HREF="#introduction">Introduction</A></LI>
<LI><A HREF="#numeric_cast"><CODE>numeric_cast</CODE></A></LI>
<LI><A HREF="#examples">Examples</A></LI>
</UL> <HR>
<H2><A NAME="introduction">Introduction</A></H2>
<P>The lack of preservation of range makes conversions between numeric
types error prone. This is true for both implicit conversions and explicit
conversions (through static_cast). <A HREF="#numeric_cast"> numeric_cast</A>
detects loss of range when a numeric type is converted, and throws an
exception if the range cannot be preserved.</P>
<P>There are several situations where conversions are unsafe: </P>
<UL>
<LI>Conversions from an integral type with a wider range than the target
integral type.</LI>
<LI> Conversions from unsigned to signed (and vice versa) integral
types.</LI>
<LI> Conversions from floating point types to integral types.</LI>
</UL>
<P>The C++ Standard does not specify the behavior when a numeric type is
assigned a value that cannot be represented by the type, except for unsigned
integral types [3.9.1.4], which must obey the laws of arithmetic modulo
2<SUP>n</SUP> (this implies that the result will be reduced modulo the number
that is one greater than the largest value that can be represented). The fact
that the behavior for overflow is undefined for all conversions (except the
aforementioned unsigned to unsigned) makes any code that may produce positive
or negative overflows exposed to portability issues.</P>
<P>numeric_cast adheres to the rules for implicit conversions mandated by
the C++ Standard, such as truncating floating point types when converting to
integral types. The implementation must guarantee that for a conversion to a
type that can hold all possible values of the source type, there will be no
runtime overhead. <BR> <BR> </P> <HR>
<H2><A NAME="numeric_cast"><CODE>numeric_cast</CODE></A></H2>
<BLOCKQUOTE>
<PRE>template&lt;typename Target, typename Source&gt; inline
typename boost::numeric::converter&lt;Target,Source&gt;::result_type
numeric_cast ( Source arg )
{
return boost::numeric::converter&lt;Target,Source&gt;::convert(arg);
}
</PRE> </BLOCKQUOTE>
<P>numeric_cast returns the result of converting a value of type Source to a value of type
Target. If out-of-range is detected, an exception is thrown (see
<A HREF="converter_policies.html#bad_numc">bad_numeric_cast</A>, <A
HREF="converter_policies.html#posovr">positive_overflow</A> and
<A HREF="converter_policies.html#negovr">negative_overflow</A>). <BR> <BR> </P> <HR>
<H2><A NAME="examples">Examples</A></H2>
<P>The following example performs some typical conversions between numeric
types: </P>
<BLOCKQUOTE>
<PRE>#include &lt;boost/numeric/conversion/cast.hpp&gt;
#include &lt;iostream&gt;
int main()
{
using boost::numeric_cast;
using boost::numeric::bad_numeric_cast;
using boost::numeric::positive_overflow;
using boost::numeric::negative_overflow;
try
{
int i=42;
short s=numeric_cast&lt;short&gt;(i); // This conversion succeeds (is in range)
}
catch(negative_overflow&amp; e) {
std::cout &lt;&lt; e.what();
}
catch(positive_overflow&amp; e) {
std::cout &lt;&lt; e.what();
}
try
{
float f=-42.1234;
// This will cause a boost::numeric::negative_overflow exception to be thrown
unsigned int i=numeric_cast&lt;unsigned int&gt;(f);
}
catch(bad_numeric_cast&amp; e) {
std::cout &lt;&lt; e.what();
}
double d= f + numeric_cast&lt;double&gt;(123); // int -> double
unsigned long l=std::numeric_limits&lt;unsigned long&gt;::max();
try
{
// This will cause a boost::numeric::positive_overflow exception to be thrown
// NOTE: *operations* on unsigned integral types cannot cause overflow
// but *conversions* to a signed type ARE range checked by numeric_cast.
unsigned char c=numeric_cast&lt;unsigned char&gt;(l);
}
catch(positive_overflow&amp; e) {
std::cout &lt;&lt; e.what();
}
return 0;
}</PRE> </BLOCKQUOTE> <BR> <BR> <HR>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 20 May 2006</P>
<p>© Copyright Boost 1999</p>
<p>© Copyright Fernando Luis Cacciola Carballal, 1999,2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
+1 -3
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@@ -15,7 +15,7 @@
The lack of preservation of range makes conversions between numeric types
error prone. This is true for both implicit conversions and explicit
conversions (through `static_cast`).
[link numeric_conversion_numeric_cast `numeric_cast`]
[link boost_numericconversion.improved_numeric_cast__.numeric_cast `numeric_cast`]
detects loss of range when a numeric type is converted, and throws an
exception if the range cannot be preserved.
@@ -42,8 +42,6 @@ be no runtime overhead.
[endsect]
[#numeric_conversion_numeric_cast]
[section numeric_cast]
template<typename Target, typename Source> inline
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<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<LINK REL="stylesheet" TYPE="text/css" HREF="../../../../boost.css">
<TITLE>Boost Numeric Conversion Library - Type Requirements and User-defined-types support</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000ff" VLINK="#800080">
<TABLE BORDER="0" CELLPADDING="7" CELLSPACING="0" WIDTH="100%"
SUMMARY="header">
<TR>
<TH VALIGN="top" WIDTH="300">
<H3><A HREF="../../../../index.htm"><IMG HEIGHT="86" WIDTH="277"
ALT="C++ Boost" SRC="../../../../boost.png" BORDER="0"></A></H3> </TH>
<TH VALIGN="top">
<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1 ALIGN="center">Type Requirements<br>and<br>User-defined-types support</H1>
</TH>
</TR>
</TABLE> <HR>
<H2>Contents</H2>
<DL CLASS="page-index">
<DT><A HREF="#req">Type Requirements</A></DT>
<DT><A HREF="#sem">UDT's special semantics</A></DT>
<DT><A HREF="#hooks">Special Policies</A></DT>
</DL>
<HR>
<H2><A NAME="req"></A>Type Requirements</H2>
<P>Both arithmetic (built-in) and user-defined numeric types require proper specialization of
<CODE>std::numeric_limits<></CODE> (that is, with (in-class) integral constants).<br>
The library uses <CODE>std::numeric_limits&lt;T&gt;::is_specialized</CODE> to detect whether
the type is builtin or user defined, and <CODE>std::numeric_limits&lt;T&gt;::is_integer,
std::numeric_limits&lt;T&gt;::is_signed</CODE>
to detect whether the type is integer or floating point; and whether it is signed/unsigned.</P>
<P>The default Float2IntRounder policies uses unqualified calls to functions <CODE>floor()
and ceil()</CODE>; but the standard functions are introduced in scope by a
using directive:</P>
<PRE>using std::floor ; return floor(s); </PRE>
<P>Therefore, for builtin arithmetic types, the std functions will be used.
User defined types should provide overloaded versions of these functions in
order to use the default rounder policies. If these overloads are defined within a user namespace
argument dependent lookup (ADL) should find them, but if your compiler has a weak ADL
you might need to put these functions some place else or write your own rounder policy.</P>
<P>The default Trunc&lt;&gt; rounder policy needs to determine if the source value
is positive or not, and for this it evaluates the expression &quot;s &lt; static_cast&lt;S&gt;(0)&quot;.
Therefore, user defined types require a visible operator &lt; in order to use
the Trunc<> policy (the default).<br>
</P>
<HR>
<H2><A NAME="sem"></A>UDT's special semantics</H2>
<p><u>Conversion Traits</u></p>
<p>If a User Defined Type is involved in a conversion, it is <i>assumed</i> that
the UDT has <a href="definitions.html#range">wider range</a> than any built-in
type, and consequently the values of some <code>converter_traits&lt;&gt;</code>
members are hardwired regardless of the reality. The following table summarizes
this:</p>
<li>Target=UDT and Source=built-in
<blockquote><code>subranged=false</code><br>
<code>supertype=Target</code><br>
<code>subtype=Source</code></blockquote>
</li>
<li>Target=built-in and Source=UDT
<blockquote><code>subranged=true</code><br>
<code>supertype=Source</code><br>
<code>subtype=Target</code></blockquote>
</li>
<li>Target=UDT and Source=UDT
<blockquote><code>subranged=false</code><br>
<code>supertype=Target</code><br>
<code>subtype=Source</code></blockquote>
</li>
<p>The Traits member <code>udt_mixture</code> can be used to detect whether a
UDT is involved and to infer the validity of the other members as shown above.</p>
<p><u>Range Checking</u></p>
<p>Because User Defined Numeric Types might have peculiar ranges (such as an unbounded
range), this library does not attempt to supply a meaningful range checking
logic when UDTs are involved in a conversion. Therefore, if either Target or
Source are not built-in types, the bundled range checking of the <code>converter&lt;&gt;</code>
function object is automatically disabled. However, it is possible to supply
a user-defined range-checker. See <A HREF="#hooks">Special Policies</A></p>
<HR>
<H2><A NAME="hooks"></A>Special Policies</H2>
<p>There are two components of the <code>converter&lt;&gt;</code> class that might
require special behavior if User Defined Numeric Types are involved: the Range
Checking and the Raw Conversion.</p>
<p>When both Target and Source are built-in types, the converter class uses an
<i>internal</i> range checking logic which is optimized and customized for the
combined properties of the types.<br>
However, this internal logic is disabled when either type is User Defined. In
this case, the user can specify an <i>external</i> range checking policy which
will be used in place of the internal code.
See <a HREF="converter_policies.html#rc">UserRangeChecker</a> policy for details.</p>
<p>The converter class performs the actual conversion using a Raw Converter policy.
The default raw converter simply performs a <code>&quot;static_cast&lt;Target&gt;(source)&quot;.</code><br>
However, if the a UDT is involved, the static_cast might not work. In this case,
the user can implement and pass a different raw converter policy.
See <a HREF="converter_policies.html#rawc">RawConverter</a> policy for details </p>
<HR>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
<HR>
<P>Revised 23 June 2004</P>
<p>© Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
</BODY>
</HTML>
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@@ -8,8 +8,6 @@
http://www.boost.org/LICENSE_1_0.txt)
]
[#numeric_conversion_requirements]
[section Type Requirements and User-defined-types support]
[section Type Requirements]
@@ -49,7 +47,7 @@ is positive or not, and for this it evaluates the expression
[heading Conversion Traits]
If a User Defined Type is involved in a conversion, it is ['assumed] that
the UDT has [link numeric_conversion_definitions_range wider range]
the UDT has [link boost_numericconversion.definitions.range_and_precision wider range]
than any built-in type, and consequently the values
of some `converter_traits<>` members are hardwired regardless of the reality.
The following table summarizes this:
@@ -80,12 +78,10 @@ checking logic when UDTs are involved in a conversion. Therefore, if either
Target or Source are not built-in types, the bundled range checking of the
`converter<>` function object is automatically disabled. However, it is possible
to supply a user-defined range-checker. See
[link numeric_conversion_requirements_hooks Special Policies]
[link boost_numericconversion.type_requirements_and_user_defined_types_support.special_policies Special Policies]
[endsect]
[#numeric_conversion_requirements_hooks]
[section Special Policies]
There are two components of the `converter<>` class that might require special
@@ -99,14 +95,14 @@ of the types.
However, this internal logic is disabled when either type is User Defined.
In this case, the user can specify an ['external] range checking policy which will be
used in place of the internal code. See
[link numeric_conversion_policy_user_range_checker UserRangeChecker] policy for details.
[link boost_numericconversion.numeric_converter_policy_classes.policy_userrangechecker UserRangeChecker] policy for details.
The converter class performs the actual conversion using a Raw Converter policy.
The default raw converter simply performs a `static_cast<Target>(source)`.
However, if the a UDT is involved, the `static_cast` might not work. In this case,
the user can implement and pass a different raw converter policy.
See [link numeric_conversion_policy_raw_converter RawConverter] policy for details
See [link boost_numericconversion.numeric_converter_policy_classes.policy_rawconverter RawConverter] policy for details
[endsect]
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@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
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@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -12,7 +12,7 @@
#include <typeinfo> // for std::bad_cast
#include <cmath> // for std::floor and std::ceil
#include <boost/config/no_tr1/cmath.hpp> // for std::floor and std::ceil
#include <functional>
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
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@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
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<html>
<head>
<meta http-equiv="refresh" content="0; URL=doc/index.html">
<meta http-equiv="refresh" content="0; URL=doc/html/index.html">
</head>
<body>
Automatic redirection failed, please go to
<a href="doc/index.html">doc/index.html</a>.&nbsp;<hr>
<p>© Copyright Beman Dawes, 2001</p>
<a href="doc/html/index.html">doc/index.html</a>.&nbsp;<hr>
<p> Copyright Beman Dawes, 2001</p>
<p>Distributed under the Boost Software License, Version 1.0. (See accompanying
file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy
file <a href="../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy
at <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</p>
</body>
</html>
</html>
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# Boost Numeric Conversion Library test Jamfile
#
# Copyright (C) 2003, Fernando Luis Cacciola Carballal.
#
# Distributed under the Boost Software License, Version 1.0. (See
# accompanying file LICENSE_1_0.txt or copy at
# http://www.boost.org/LICENSE_1_0.txt)
test-suite numeric/conversion :
[ run bounds_test.cpp ]
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// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
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@@ -1,4 +1,4 @@
// © Copyright Fernando Luis Cacciola Carballal 2000-2004
// (c) Copyright Fernando Luis Cacciola Carballal 2000-2004
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
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@@ -1,4 +1,4 @@
// (C) 2003, Fernando Luis Cacciola Carballal.
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
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@@ -1,4 +1,4 @@
// (C) 2003, Fernando Luis Cacciola Carballal.
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
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@@ -1,4 +1,4 @@
// (C) 2003, Fernando Luis Cacciola Carballal.
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
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@@ -1,4 +1,4 @@
// (C) 2003, Fernando Luis Cacciola Carballal.
// Copyright (C) 2003, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
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@@ -1,4 +1,4 @@
// (C) 2005, Fernando Luis Cacciola Carballal.
// Copyright (C) 2005, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
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@@ -1,4 +1,4 @@
// (C) 2003, Fernando Luis Cacciola Carballal.
// (C) Copyright 2003, Fernando Luis Cacciola Carballal.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at