Merge pull request #115 from Lastique/feature/remove_static_assert

Remove dependencies on Boost.StaticAssert
Remove dependencies on Boost.StaticAssert.
2026-07-21 13:43:36 +00:00 · 2026-04-25 20:51:34 +03:00 · 2026-01-22 22:52:11 +03:00 · 2026-01-04 11:27:21 +03:00 · 2025-12-29 12:31:14 +03:00 · 2025-12-24 20:23:02 +03:00
64 changed files with 227 additions and 1335 deletions
@@ -0,0 +1,11 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+        interval: "weekly"
@@ -17,29 +17,31 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - toolset: gcc-7
-            cxxstd: "03,11,14,17"
-            os: ubuntu-18.04
-          - toolset: gcc-9
+          - toolset: gcc-12
            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
-          - toolset: gcc-10
-            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            os: ubuntu-22.04
            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
            linkflags: "linkflags=--coverage -lasan -lubsan"
-            gcov_tool: "gcov-10"
-          - toolset: clang
-            compiler: clang++-10
+            gcov_tool: "gcov-12"
+            launcher: "testing.launcher=LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libasan.so.8"
+          - toolset: gcc-11
            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-20.04
+            os: ubuntu-22.04
+            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
+            linkflags: "linkflags=--coverage -lasan -lubsan"
+            gcov_tool: "gcov-11"
+            launcher: "testing.launcher=LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libasan.so.7"
+          - toolset: clang
+            compiler: clang++
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-24.04
            cxxflags: "cxxflags=-fsanitize=address,undefined,integer -fno-sanitize-recover=undefined"
            linkflags: "linkflags=-fsanitize=address,undefined,integer"

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6

      - name: Install packages
        if: matrix.install
@@ -68,7 +70,7 @@ jobs:
          python tools/boostdep/depinst/depinst.py --include benchmark --include example --include examples --include tools --git_args "--depth 10 --jobs 3" $LIBRARY
          ./bootstrap.sh
          ./b2 -d0 headers
-          ./b2 -j4 variant=debug tools/inspect/build
+          ./b2 -j4 variant=debug tools/inspect

      - name: Run tests
        run: |
@@ -83,9 +85,9 @@ jobs:

          echo -e "#!/bin/bash\nexec ${{matrix.gcov_tool}} \"\$@\"" > $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh
          chmod +x $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh
-          wget https://github.com/linux-test-project/lcov/archive/v1.15.zip
-          unzip v1.15.zip
-          LCOV="`pwd`/lcov-1.15/bin/lcov --gcov-tool $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh"
+          wget https://github.com/linux-test-project/lcov/archive/v1.16.zip
+          unzip v1.16.zip
+          LCOV="`pwd`/lcov-1.16/bin/lcov --gcov-tool $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh"

          echo "$LCOV --directory ../boost-root/bin.v2/libs/$LIBRARY/ --base-directory `pwd`/libs/$LIBRARY/test --capture --output-file $GITHUB_WORKSPACE/coveralls/coverage.info"
          $LCOV --directory ../boost-root/bin.v2/libs/$LIBRARY/ --base-directory ../boost-root/ --capture --output-file $GITHUB_WORKSPACE/coveralls/coverage.info
@@ -113,19 +115,19 @@ jobs:
            cxxstd: "14,17,latest"
            addrmd: 32,64
            os: windows-2022
-          - toolset: msvc-14.2
+          - toolset: msvc
            cxxstd: "14,17,latest"
            addrmd: 32,64
-            os: windows-2019
+            os: windows-2025
          - toolset: gcc
            cxxstd: "03,11,14,17,2a"
            addrmd: 64
-            os: windows-2019
+            os: windows-2025

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v6

      - name: Setup Boost
        shell: cmd
@@ -13,16 +13,13 @@ target_include_directories( boost_variant INTERFACE include )
 target_link_libraries( boost_variant
    INTERFACE
        Boost::assert
-        Boost::bind
        Boost::config
        Boost::container_hash
        Boost::core
        Boost::detail
        Boost::integer
-        Boost::move
        Boost::mpl
        Boost::preprocessor
-        Boost::static_assert
        Boost::throw_exception
        Boost::type_index
        Boost::type_traits
@@ -5,8 +5,8 @@ Boost.Variant, part of collection of the [Boost C++ Libraries](https://github.co

@               | Build         | Tests coverage | More info
 ----------------|-------------- | -------------- |-----------
-Develop branch: | [![CI](https://github.com/boostorg/variant/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/variant/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/bijfdoy7byfgc6e2/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/variant-ykfti/branch/develop) | [![Coverage Status](https://coveralls.io/repos/boostorg/variant/badge.png?branch=develop)](https://coveralls.io/r/apolukhin/variant?branch=develop) | [details...](http://www.boost.org/development/tests/develop/developer/variant.html)
-Master branch:  | [![CI](https://github.com/boostorg/variant/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/variant/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/bijfdoy7byfgc6e2/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/variant-ykfti/branch/master) | [![Coverage Status](https://coveralls.io/repos/boostorg/variant/badge.png?branch=master)](https://coveralls.io/r/apolukhin/variant?branch=master)  | [details...](http://www.boost.org/development/tests/master/developer/variant.html)
+Develop branch: | [![CI](https://github.com/boostorg/variant/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/variant/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/bijfdoy7byfgc6e2/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/variant-ykfti/branch/develop) | [![Coverage Status](https://coveralls.io/repos/boostorg/variant/badge.png?branch=develop)](https://coveralls.io/r/apolukhin/variant?branch=develop) | [details...](https://regression.boost.io/develop/developer/variant.html)
+Master branch:  | [![CI](https://github.com/boostorg/variant/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/variant/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/bijfdoy7byfgc6e2/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/variant-ykfti/branch/master) | [![Coverage Status](https://coveralls.io/repos/boostorg/variant/badge.png?branch=master)](https://coveralls.io/r/apolukhin/variant?branch=master)  | [details...](https://regression.boost.io/master/developer/variant.html)


 [Latest developer documentation](https://www.boost.org/doc/libs/develop/doc/html/variant.html)
@@ -0,0 +1,34 @@
+# Copyright René Ferdinand Rivera Morell 2023-2024
+# 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)
+
+require-b2 5.2 ;
+
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/container_hash//boost_container_hash
+    /boost/core//boost_core
+    /boost/detail//boost_detail
+    /boost/integer//boost_integer
+    /boost/mpl//boost_mpl
+    /boost/preprocessor//boost_preprocessor
+    /boost/throw_exception//boost_throw_exception
+    /boost/type_index//boost_type_index
+    /boost/type_traits//boost_type_traits
+    /boost/utility//boost_utility ;
+
+project /boost/variant
+    : common-requirements
+        <include>include
+    ;
+
+explicit
+    [ alias boost_variant : : : : <library>$(boost_dependencies) ]
+    [ alias all : boost_variant test ]
+    ;
+
+call-if : boost-library variant
+    ;
+
@@ -3,7 +3,7 @@
  "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
 <!--
    Copyright 2003, Eric Friedman, Itay Maman.
-    Copyright 2013-2023 Antony Polukhin.
+    Copyright 2013-2026 Antony Polukhin.

    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)
@@ -91,8 +91,6 @@
            <code><functionname>apply_visitor</functionname></code> on the
            stored visitor using the given operands.</simpara>
          </description>
-          <notes>Version with variadic templates is used by default if
-          <macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname> is not defined.</notes>
        </overloaded-method>
      </method-group>
    </class>
@@ -111,8 +109,7 @@
        <simpara>See <code><classname>apply_visitor_delayed_t</classname></code>
            which is used when <code>Visitor</code> has <code>result_type</code>
            typedef.</simpara>
-        <simpara>Available only if macro
-          <macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname> is not defined and
+        <simpara>Available only if
          compiler supports <code>decltype(auto)</code> and <code>decltype(some-expression)</code>.</simpara>
      </description>

@@ -2,7 +2,7 @@
 <!DOCTYPE header PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
  "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
 <!--
-    Copyright 2013-2023 Antony Polukhin.
+    Copyright 2013-2026 Antony Polukhin.

    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)
@@ -13,22 +13,6 @@
  <para>Provides declarations of <functionname>apply_visitor</functionname> for three or more
    <code><classname>variant</classname></code> parameters.</para>

-    <macro name="BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS">
-      <purpose>
-        <simpara>Controls maximum amount of <code><classname>variant</classname></code>
-          parameters for multi visistors. Not used when <code>std::tuple</code> is available and
-          <code><macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname></code>
-          is not defined.</simpara>
-      </purpose>
-
-      <description>
-        <para><emphasis role="bold">Note</emphasis>: Default amount is 4. Define it 
-          to bigger value before including &lt;boost/variant/multivisitors.hpp&gt; to
-          increase maximum amount of <code><classname>variant</classname></code>
-          parameters for <functionname>apply_visitor</functionname>.</para>
-      </description>
-    </macro>
-
  <namespace name="boost">
    <overloaded-function name="apply_visitor /*three or more variant parameters*/">
      <description>
@@ -2,7 +2,7 @@
 <!DOCTYPE header PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
  "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
 <!--
-    Copyright 2013-2023 Antony Polukhin.
+    Copyright 2013-2026 Antony Polukhin.

    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)
@@ -104,11 +104,6 @@
          <listitem><code>Sequence</code> must meet the requirements of
            <libraryname>MPL</libraryname>'s <emphasis>Sequence</emphasis>
            concept.</listitem>
-          <listitem>Due to standard conformance problems in several compilers,
-            <code>make_recursive_variant_over</code> may not be supported on
-            your compiler. See
-            <code><macroname>BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT</macroname></code>
-            for more information.</listitem>
        </itemizedlist>
      </description>
    </class>
@@ -951,11 +951,6 @@
          <listitem><code>Sequence</code> must meet the requirements of
            <libraryname>MPL</libraryname>'s <emphasis>Sequence</emphasis>
            concept.</listitem>
-          <listitem>Due to standard conformance problems in several compilers,
-            <code>make_variant_over</code> may not be supported on your
-            compiler. See
-            <code><macroname>BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT</macroname></code>
-            for more information.</listitem>
        </itemizedlist>
      </description>
    </class>
@@ -3,7 +3,7 @@
  "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
 <!--
    Copyright 2003, Eric Friedman, Itay Maman.
-    Copyright 2016-2023 Antony Polukhin.
+    Copyright 2016-2026 Antony Polukhin.

    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)
@@ -19,36 +19,6 @@
    class templates and the <code>boost::recursive_variant_</code> tag type.
    Also defines several preprocessor symbols, as described below.</para>

-  <macro name="BOOST_VARIANT_LIMIT_TYPES">
-    <purpose>
-      <simpara>Expands to the length of the
-        template parameter list for
-        <code><classname>variant</classname></code>. Not used if
-        <code><macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname></code>
-        is not defined. 
-      </simpara>
-    </purpose>
-
-    <description>
-      <para><emphasis role="bold">Note</emphasis>: Conforming
-        implementations of <code>variant</code> must allow at least ten
-        template arguments. That is, BOOST_VARIANT_LIMIT_TYPES must be greater
-        or equal to <code>10</code>.</para>
-    </description>
-  </macro>
-
-  <macro name="BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES">
-    <purpose>
-      <simpara>If this macro is defined, then library won't use C++11 variadic templates.
-        Users may define this macro to make 
-        <code><macroname>BOOST_VARIANT_ENUM_PARAMS</macroname></code>
-        and <code><macroname>BOOST_VARIANT_ENUM_SHIFTED_PARAMS</macroname></code> expand
-        to a comma-separated sequence instead of variadic templates. Define this macro if
-        your compiler has problems with compilation of variadic templates.
-      </simpara>
-    </purpose>
-  </macro>
-
  <macro name="BOOST_VARIANT_ENUM_PARAMS" kind="functionlike">
    <macro-parameter name="param"/>

@@ -58,9 +28,7 @@
    </purpose>

    <description>
-      <para> When variadic templates are available and
-        <code><macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname></code>
-        is not defined, expands to variadic template list in the following manner:
+      <para> Expands to variadic template list in the following manner:
        <code><programlisting>
            BOOST_VARIANT_ENUM_PARAMS(T)                    => T0, TN...
            BOOST_VARIANT_ENUM_PARAMS(class T)              => class T0, class... TN
@@ -97,9 +65,7 @@
    </purpose>

    <description>
-      <para> When variadic templates are available and
-        <code><macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname></code>
-        is not defined, expands to variadic template list in the following manner:
+      <para> Expands to variadic template list in the following manner:
        <code><programlisting>
            BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)                    => TN...
            BOOST_VARIANT_ENUM_SHIFTED_PARAMS(class T)              => class... TN
@@ -125,21 +91,6 @@
    </description>
  </macro>

-  <macro name="BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT">
-    <purpose>
-      <simpara>Indicates absence of support for specifying the bounded types
-        of a <code><classname>variant</classname></code> by the elements of a
-        type sequence.</simpara>
-    </purpose>
-
-    <description>
-      <para>Defined only if
-        <code><classname>make_variant_over</classname></code> and
-        <code><classname>make_recursive_variant_over</classname></code>
-        are not supported for some reason on the target compiler.</para>
-    </description>
-  </macro>
-
  <macro name="BOOST_VARIANT_DO_NOT_SPECIALIZE_STD_HASH">
    <purpose>
      <simpara>Define this macro if you do not wish to have a <code><classname>std::hash</classname></code> specialization for
@@ -3,7 +3,7 @@
  "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd">
 <!--
    Copyright 2003, Eric Friedman, Itay Maman.
-    Copyright 2013-2023 Antony Polukhin.
+    Copyright 2013-2026 Antony Polukhin.

    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)
@@ -90,13 +90,6 @@ typedef <classname>mpl::push_front</classname>&lt; types_initial, int &gt;::type

  </para>

-  <para><emphasis role="bold">Portability</emphasis>: Unfortunately, due to
-    standard conformance issues in several compilers,
-    <code>make_variant_over</code> is not universally available. On these
-    compilers the library indicates its lack of support for the syntax via the
-    definition of the preprocessor symbol
-    <code><macroname>BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT</macroname></code>.</para>
-
 </section>

 <section id="variant.tutorial.recursive">
@@ -407,12 +400,6 @@ assert(
 </programlisting>
  </para>

-  <para>Finally, we must note that multi visitation does not support 
-    &quot;delayed&quot; form of
-    <code><functionname>apply_visitor</functionname> if
-    <macroname>BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</macroname> is defined</code>.
-  </para>
-
 </section>


@@ -27,7 +27,7 @@
  </copyright>

  <copyright>
-    <year>2014-2023</year>
+    <year>2014-2026</year>
    <holder>Antony Polukhin</holder>
  </copyright>
  <legalnotice>
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2002-2003 Eric Friedman
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -21,12 +21,10 @@
 #   include <boost/variant/detail/has_result_type.hpp>
 #endif

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-#   include <boost/core/enable_if.hpp>
-#   include <boost/type_traits/is_lvalue_reference.hpp>
-#   include <boost/type_traits/is_same.hpp>
-#   include <boost/move/utility_core.hpp> // for boost::move, boost::forward
-#endif
+#include <boost/core/enable_if.hpp>
+#include <boost/type_traits/is_lvalue_reference.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <utility>

 namespace boost {

@@ -63,33 +61,20 @@ public: // structors

 public: // visitor interfaces

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-
    template <typename Value2>
        typename enable_if_c<MoveSemantics && is_same<Value2, Value2>::value, result_type>::type
    operator()(Value2&& value2)
    {
-        return visitor_(::boost::move(value1_), ::boost::forward<Value2>(value2));
+        return visitor_(std::move(value1_), std::forward<Value2>(value2));
    }

    template <typename Value2>
        typename disable_if_c<MoveSemantics && is_same<Value2, Value2>::value, result_type>::type
    operator()(Value2&& value2)
    {
-        return visitor_(value1_, ::boost::forward<Value2>(value2));
+        return visitor_(value1_, std::forward<Value2>(value2));
    }

-#else
-
-    template <typename Value2>
-        result_type
-    operator()(Value2& value2)
-    {
-        return visitor_(value1_, value2);
-    }
-
-#endif
-
 private:
    apply_visitor_binary_invoke& operator=(const apply_visitor_binary_invoke&);
 };
@@ -117,8 +102,6 @@ public: // structors

 public: // visitor interfaces

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-
    template <typename Value1>
        typename enable_if_c<MoveSemantics && is_same<Value1, Value1>::value, result_type>::type
    operator()(Value1&& value1)
@@ -129,7 +112,7 @@ public: // visitor interfaces
            , ! ::boost::is_lvalue_reference<Value1>::value
            > invoker(visitor_, value1);

-        return boost::apply_visitor(invoker, ::boost::move(visitable2_));
+        return boost::apply_visitor(invoker, std::move(visitable2_));
    }

    template <typename Value1>
@@ -145,23 +128,6 @@ public: // visitor interfaces
        return boost::apply_visitor(invoker, visitable2_);
    }

-#else
-
-    template <typename Value1>
-        result_type
-    operator()(Value1& value1)
-    {
-        apply_visitor_binary_invoke<
-              Visitor
-            , Value1
-            , false
-            > invoker(visitor_, value1);
-
-        return boost::apply_visitor(invoker, visitable2_);
-    }
-
-#endif
-
 private:
    apply_visitor_binary_unwrap& operator=(const apply_visitor_binary_unwrap&);

@@ -173,8 +139,6 @@ private:
 // nonconst-visitor version:
 //

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-
 template <typename Visitor, typename Visitable1, typename Visitable2>
 inline typename Visitor::result_type
 apply_visitor( Visitor& visitor, Visitable1&& visitable1, Visitable2&& visitable2)
@@ -183,29 +147,13 @@ apply_visitor( Visitor& visitor, Visitable1&& visitable1, Visitable2&& visitable
          Visitor, Visitable2, ! ::boost::is_lvalue_reference<Visitable2>::value
        > unwrapper(visitor, visitable2);

-    return boost::apply_visitor(unwrapper, ::boost::forward<Visitable1>(visitable1));
+    return boost::apply_visitor(unwrapper, std::forward<Visitable1>(visitable1));
 }

-#else
-
-template <typename Visitor, typename Visitable1, typename Visitable2>
-inline typename Visitor::result_type
-apply_visitor( Visitor& visitor, Visitable1& visitable1, Visitable2& visitable2)
-{
-    ::boost::detail::variant::apply_visitor_binary_unwrap<
-          Visitor, Visitable2, false
-        > unwrapper(visitor, visitable2);
-
-    return boost::apply_visitor(unwrapper, visitable1);
-}
-
-#endif
-
 //
 // const-visitor version:
 //

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES

 template <typename Visitor, typename Visitable1, typename Visitable2>
 inline typename Visitor::result_type
@@ -215,24 +163,9 @@ apply_visitor( const Visitor& visitor , Visitable1&& visitable1 , Visitable2&& v
          const Visitor, Visitable2, ! ::boost::is_lvalue_reference<Visitable2>::value
        > unwrapper(visitor, visitable2);

-    return boost::apply_visitor(unwrapper, ::boost::forward<Visitable1>(visitable1));
+    return boost::apply_visitor(unwrapper, std::forward<Visitable1>(visitable1));
 }

-#else
-
-template <typename Visitor, typename Visitable1, typename Visitable2>
-inline typename Visitor::result_type
-apply_visitor( const Visitor& visitor , Visitable1& visitable1 , Visitable2& visitable2)
-{
-    ::boost::detail::variant::apply_visitor_binary_unwrap<
-          const Visitor, Visitable2, false
-        > unwrapper(visitor, visitable2);
-
-    return boost::apply_visitor(unwrapper, visitable1);
-}
-
-#endif
-

 #if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)

@@ -263,13 +196,13 @@ public: // visitor interfaces
    template <typename Value2>
    decltype(auto) operator()(Value2&& value2, typename enable_if_c<MoveSemantics && is_same<Value2, Value2>::value, bool>::type = true)
    {
-        return visitor_(::boost::move(value1_), ::boost::forward<Value2>(value2));
+        return visitor_(std::move(value1_), std::forward<Value2>(value2));
    }

    template <typename Value2>
    decltype(auto) operator()(Value2&& value2, typename disable_if_c<MoveSemantics && is_same<Value2, Value2>::value, bool>::type = true)
    {
-        return visitor_(value1_, ::boost::forward<Value2>(value2));
+        return visitor_(value1_, std::forward<Value2>(value2));
    }

 private:
@@ -301,7 +234,7 @@ public: // visitor interfaces
            , ! ::boost::is_lvalue_reference<Value1>::value
            > invoker(visitor_, value1);

-        return boost::apply_visitor(invoker, ::boost::move(visitable2_));
+        return boost::apply_visitor(invoker, std::move(visitable2_));
    }

    template <typename Value1>
@@ -333,7 +266,7 @@ inline decltype(auto) apply_visitor(Visitor& visitor, Visitable1&& visitable1, V
          Visitor, Visitable2, ! ::boost::is_lvalue_reference<Visitable2>::value
        > unwrapper(visitor, visitable2);

-    return boost::apply_visitor(unwrapper, ::boost::forward<Visitable1>(visitable1));
+    return boost::apply_visitor(unwrapper, std::forward<Visitable1>(visitable1));
 }

 template <typename Visitor, typename Visitable1, typename Visitable2>
@@ -347,7 +280,7 @@ inline decltype(auto) apply_visitor(const Visitor& visitor, Visitable1&& visitab
          const Visitor, Visitable2, ! ::boost::is_lvalue_reference<Visitable2>::value
        > unwrapper(visitor, visitable2);

-    return boost::apply_visitor(unwrapper, ::boost::forward<Visitable1>(visitable1));
+    return boost::apply_visitor(unwrapper, std::forward<Visitable1>(visitable1));
 }


@@ -15,7 +15,7 @@

 #include <boost/variant/detail/apply_visitor_unary.hpp>
 #include <boost/variant/detail/apply_visitor_binary.hpp>
-#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+#include <boost/variant/variant_fwd.hpp>


 #include <boost/variant/detail/has_result_type.hpp>
@@ -57,8 +57,6 @@ public: // structors
    {
    }

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
 public: // N-ary visitor interface
    template <typename... Visitables>
    result_type operator()(Visitables&... visitables) const
@@ -66,26 +64,6 @@ public: // N-ary visitor interface
        return apply_visitor(visitor_, visitables...);
    }

-#else // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
-public: // unary visitor interface
-
-    template <typename Visitable>
-    result_type operator()(Visitable& visitable) const
-    {
-        return apply_visitor(visitor_, visitable);
-    }
-
-public: // binary visitor interface
-
-    template <typename Visitable1, typename Visitable2>
-    result_type operator()(Visitable1& visitable1, Visitable2& visitable2) const
-    {
-        return apply_visitor(visitor_, visitable1, visitable2);
-    }
-
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
 private:
    apply_visitor_delayed_t& operator=(const apply_visitor_delayed_t&);

@@ -100,8 +78,7 @@ inline typename boost::enable_if<
    return apply_visitor_delayed_t<Visitor>(visitor);
 }

-#if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276) \
-    && !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
+#if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO)

 template <typename Visitor>
 class apply_visitor_delayed_cpp14_t
@@ -137,8 +114,7 @@ inline  typename boost::disable_if<
    return apply_visitor_delayed_cpp14_t<Visitor>(visitor);
 }

-#endif // !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
-            // && !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
+#endif // !defined(BOOST_NO_CXX14_DECLTYPE_AUTO)


 } // namespace boost
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2002-2003 Eric Friedman
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -14,7 +14,7 @@
 #define BOOST_VARIANT_DETAIL_APPLY_VISITOR_UNARY_HPP

 #include <boost/config.hpp>
-#include <boost/move/utility.hpp>
+#include <utility>

 #if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
 #   include <boost/mpl/distance.hpp>
@@ -40,41 +40,23 @@ namespace boost {
 // nonconst-visitor version:
 //

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
 template <typename Visitor, typename Visitable>
 inline typename Visitor::result_type
 apply_visitor(Visitor& visitor, Visitable&& visitable)
 {
-    return ::boost::forward<Visitable>(visitable).apply_visitor(visitor);
+    return std::forward<Visitable>(visitable).apply_visitor(visitor);
 }
-#else
-template <typename Visitor, typename Visitable>
-inline typename Visitor::result_type
-apply_visitor(Visitor& visitor, Visitable& visitable)
-{
-    return visitable.apply_visitor(visitor);
-}
-#endif

 //
 // const-visitor version:
 //

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
 template <typename Visitor, typename Visitable>
 inline typename Visitor::result_type
 apply_visitor(const Visitor& visitor, Visitable&& visitable)
 {
-    return ::boost::forward<Visitable>(visitable).apply_visitor(visitor);
+    return std::forward<Visitable>(visitable).apply_visitor(visitor);
 }
-#else
-template <typename Visitor, typename Visitable>
-inline typename Visitor::result_type
-apply_visitor(const Visitor& visitor, Visitable& visitable)
-{
-    return visitable.apply_visitor(visitor);
-}
-#endif


 #if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
@@ -116,12 +98,12 @@ struct result_wrapper1

    Visitor&& visitor_;
    explicit result_wrapper1(Visitor&& visitor) BOOST_NOEXCEPT
-        : visitor_(::boost::forward<Visitor>(visitor))
+        : visitor_(std::forward<Visitor>(visitor))
    {}

    template <class T>
    result_type operator()(T&& val) const {
-        return visitor_(::boost::forward<T>(val));
+        return visitor_(std::forward<T>(val));
    }
 };

@@ -134,8 +116,8 @@ inline decltype(auto) apply_visitor(Visitor&& visitor, Visitable&& visitable,
        bool
    >::type = true)
 {
-    boost::detail::variant::result_wrapper1<Visitor, Visitable> cpp14_vis(::boost::forward<Visitor>(visitor));
-    return ::boost::forward<Visitable>(visitable).apply_visitor(cpp14_vis);
+    boost::detail::variant::result_wrapper1<Visitor, Visitable> cpp14_vis(std::forward<Visitor>(visitor));
+    return std::forward<Visitable>(visitable).apply_visitor(cpp14_vis);
 }

 #endif // !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman
-// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -36,42 +36,10 @@
 namespace boost {
 namespace detail { namespace variant {

-#if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 #   define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL(T,Dest,Source) \
    substitute< T , Dest , Source > \
    /**/

-#else // defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
-///////////////////////////////////////////////////////////////////////////////
-// (detail) class template rebind1
-//
-// Limited workaround in case 'substitute' metafunction unavailable.
-//
-
-template <typename T, typename U1>
-struct rebind1
-{
-private:
-    typedef typename mpl::lambda<
-          mpl::identity<T>
-        >::type le_;
-
-public:
-    typedef typename mpl::eval_if<
-          is_same< le_, mpl::identity<T> >
-        , le_ // identity<T>
-        , mpl::apply1<le_, U1>
-        >::type type;
-};
-
-#   define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_IMPL(T,Dest,Source) \
-    rebind1< T , Dest > \
-    /**/
-
-#endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction enable_recursive
 //
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman
-// Copyright (c) 2015-2023 Antony Polukhin
+// Copyright (c) 2015-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2011-2023 Antony Polukhin
+// Copyright (c) 2011-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -22,7 +22,6 @@
 #include <boost/variant/recursive_wrapper_fwd.hpp>
 #include <boost/variant/detail/move.hpp>

-#if !defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
 #   include <boost/mpl/aux_/value_wknd.hpp>
 #   include <boost/mpl/int.hpp>
 #   include <boost/mpl/iter_fold.hpp>
@@ -30,12 +29,7 @@
 #   include <boost/mpl/deref.hpp>
 #   include <boost/mpl/pair.hpp>
 #   include <boost/mpl/protect.hpp>
-#else
-#   include <boost/variant/variant_fwd.hpp>
-#   include <boost/preprocessor/cat.hpp>
-#   include <boost/preprocessor/enum.hpp>
-#   include <boost/preprocessor/repeat.hpp>
-#endif
+

 namespace boost {
 namespace detail { namespace variant {
@@ -53,8 +47,6 @@ namespace detail { namespace variant {
 // size of the variant's psuedo-variadic template parameter list.
 //

-#if !defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
 // (detail) quoted metafunction make_initializer_node
 //
 // Exposes a pair whose first type is a node in the initializer hierarchy.
@@ -81,7 +73,6 @@ struct make_initializer_node
            typedef typename unwrap_recursive<recursive_enabled_T>::type
                public_T;

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
            typedef boost::is_reference<public_T> 
                is_reference_content_t;

@@ -92,10 +83,6 @@ struct make_initializer_node

            typedef typename boost::mpl::if_<is_reference_content_t, disable_overload<public_T>, public_T&& >::type 
                param2_T;
-#else
-            typedef typename call_traits<public_T>::param_type
-                param_T;
-#endif

        public: // static functions

@@ -111,7 +98,6 @@ struct make_initializer_node
                return BOOST_MPL_AUX_VALUE_WKND(index)::value; // which
            }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
            static int initialize(void* dest, param2_T operand)
            {
                // This assert must newer trigger, because all the reference contents are
@@ -122,7 +108,6 @@ struct make_initializer_node
                new(dest) value_T( boost::detail::variant::move(operand) );
                return BOOST_MPL_AUX_VALUE_WKND(index)::value; // which
            }
-#endif
        };

        friend class initializer_node;
@@ -150,61 +135,6 @@ public: // static functions

 };

-#else // defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
-    // Obsolete. Remove.
-    #define BOOST_VARIANT_AUX_PP_INITIALIZER_TEMPLATE_PARAMS \
-          BOOST_VARIANT_ENUM_PARAMS(typename recursive_enabled_T) \
-    /**/
-
-    // Obsolete. Remove.
-    #define BOOST_VARIANT_AUX_PP_INITIALIZER_DEFINE_PARAM_T(N) \
-        typedef typename unwrap_recursive< \
-              BOOST_PP_CAT(recursive_enabled_T,N) \
-            >::type BOOST_PP_CAT(public_T,N); \
-        typedef typename call_traits< \
-              BOOST_PP_CAT(public_T,N) \
-            >::param_type BOOST_PP_CAT(param_T,N); \
-    /**/
-
-template < BOOST_VARIANT_ENUM_PARAMS(typename recursive_enabled_T) >
-struct preprocessor_list_initializer
-{
-public: // static functions
-
-    #define BOOST_VARIANT_AUX_PP_INITIALIZE_FUNCTION(z,N,_) \
-        typedef typename unwrap_recursive< \
-              BOOST_PP_CAT(recursive_enabled_T,N) \
-            >::type BOOST_PP_CAT(public_T,N); \
-        typedef typename call_traits< \
-              BOOST_PP_CAT(public_T,N) \
-            >::param_type BOOST_PP_CAT(param_T,N); \
-        static int initialize( \
-              void* dest \
-            , BOOST_PP_CAT(param_T,N) operand \
-            ) \
-        { \
-            typedef typename boost::detail::make_reference_content< \
-                  BOOST_PP_CAT(recursive_enabled_T,N) \
-                >::type internal_T; \
-            \
-            new(dest) internal_T(operand); \
-            return (N); /*which*/ \
-        } \
-        /**/
-
-    BOOST_PP_REPEAT(
-          BOOST_VARIANT_LIMIT_TYPES
-        , BOOST_VARIANT_AUX_PP_INITIALIZE_FUNCTION
-        , _
-        )
-
-    #undef BOOST_VARIANT_AUX_PP_INITIALIZE_FUNCTION
-
-};
-
-#endif // BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE workaround
-
 }} // namespace detail::variant
 } // namespace boost

@@ -216,8 +146,6 @@ public: // static functions
 // most appropriate to the current compiler.
 //

-#if !defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
 #define BOOST_VARIANT_AUX_INITIALIZER_T( mpl_seq, typename_base ) \
    ::boost::mpl::iter_fold< \
          mpl_seq \
@@ -231,19 +159,4 @@ public: // static functions
        >::type::first \
    /**/

-#else // defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
-    // Obsolete. Remove.
-    #define BOOST_VARIANT_AUX_PP_INITIALIZER_TEMPLATE_ARGS(typename_base) \
-          BOOST_VARIANT_ENUM_PARAMS(typename_base) \
-        /**/
-
-#define BOOST_VARIANT_AUX_INITIALIZER_T( mpl_seq, typename_base ) \
-    ::boost::detail::variant::preprocessor_list_initializer< \
-          BOOST_VARIANT_ENUM_PARAMS(typename_base) \
-        > \
-    /**/
-
-#endif // BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE workaround
-
 #endif // BOOST_VARIANT_DETAIL_INITIALIZER_HPP
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2002-2003 Eric Friedman, Itay Maman
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -19,8 +19,7 @@
 #include <boost/preprocessor/cat.hpp>
 #include <boost/preprocessor/enum.hpp>

-namespace boost {
-namespace detail { namespace variant {
+namespace boost { namespace detail { namespace variant {

 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction make_variant_list
@@ -32,42 +31,12 @@ namespace detail { namespace variant {
 // declaration workaround (below).
 //

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
 template < typename... T >
 struct make_variant_list
 {
    typedef typename mpl::list< T... >::type type;
 };

-#else // defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
-template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
-struct make_variant_list
-{
-public: // metafunction result
-
-    // [Define a macro to convert any void(NN) tags to mpl::void...]
-#   define BOOST_VARIANT_AUX_CONVERT_VOID(z, N,_)  \
-        typename convert_void< BOOST_PP_CAT(T,N) >::type
-
-    // [...so that the specified types can be passed to mpl::list...]
-    typedef typename mpl::list< 
-          BOOST_PP_ENUM(
-              BOOST_VARIANT_LIMIT_TYPES
-            , BOOST_VARIANT_AUX_CONVERT_VOID
-            , _
-            )
-        >::type type;
-
-    // [...and, finally, the conversion macro can be undefined:]
-#   undef BOOST_VARIANT_AUX_CONVERT_VOID
-
-};
-
-#endif // BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES workaround
-
-}} // namespace detail::variant
-} // namespace boost
+}}} // namespace boost::detail::variant

 #endif // BOOST_VARIANT_DETAIL_MAKE_VARIANT_LIST_HPP
@@ -5,7 +5,7 @@
 //
 //  Copyright (c) 2002-2003 Eric Friedman
 //  Copyright (c) 2002 by Andrei Alexandrescu
-//  Copyright (c) 2013-2023 Antony Polukhin
+//  Copyright (c) 2013-2026 Antony Polukhin
 //
 //  Use, modification and distribution are subject to the
 //  Boost Software License, Version 1.0. (See accompanying file
@@ -22,12 +22,11 @@

 #include <boost/config.hpp>
 #include <boost/detail/workaround.hpp>
-#include <boost/move/utility_core.hpp> // for boost::move
-#include <boost/move/adl_move_swap.hpp>
+#include <utility>

 namespace boost { namespace detail { namespace variant {

-using boost::move;
+using std::move;

 //////////////////////////////////////////////////////////////////////////
 // function template move_swap
@@ -39,7 +38,8 @@ using boost::move;
 template <typename T>
 inline void move_swap(T& lhs, T& rhs)
 {
-    ::boost::adl_move_swap(lhs, rhs);
+    using std::swap;
+    swap(lhs, rhs);
 }

 }}} // namespace boost::detail::variant
@@ -3,7 +3,7 @@
 //
 //  See http://www.boost.org for most recent version, including documentation.
 //
-//  Copyright Antony Polukhin, 2013-2014.
+//  Copyright Antony Polukhin, 2013-2024.
 //
 //  Distributed under the Boost
 //  Software License, Version 1.0. (See accompanying file
@@ -17,15 +17,10 @@
 #endif

 #include <boost/variant/detail/apply_visitor_unary.hpp>
-#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-#include <boost/move/utility.hpp>
+#include <boost/variant/variant_fwd.hpp>
 #include <boost/type_traits/is_lvalue_reference.hpp>
 #include <boost/core/enable_if.hpp>

-#if defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) || defined(BOOST_NO_CXX11_HDR_TUPLE)
-#   error "This file requires <tuple> and variadic templates support"
-#endif
-
 #include <tuple>

 namespace boost { 
@@ -64,7 +59,7 @@ namespace detail { namespace variant {
    typename enable_if_c<Wrapper::MoveSemantics, typename Wrapper::T>::type
        unwrap(Wrapper& w)
    {
-        return ::boost::move(w.v);
+        return std::move(w.v);
    }

    template <typename Wrapper>
@@ -189,7 +184,7 @@ namespace detail { namespace variant {
                    ),
                std::tuple<>()
                ),
-                ::boost::forward<T1>(v1)
+                std::forward<T1>(v1)
            );
    }
    
@@ -207,7 +202,7 @@ namespace detail { namespace variant {
                    ),
                std::tuple<>()
                ),
-                ::boost::forward<T1>(v1)
+                std::forward<T1>(v1)
            );
    }

@@ -120,7 +120,7 @@ namespace detail { namespace variant {
                    ),
                std::tuple<>()
            ),
-            ::boost::forward<T1>(v1)
+            std::forward<T1>(v1)
        );
    }

@@ -142,7 +142,7 @@ namespace detail { namespace variant {
                    ),
                std::tuple<>()
            ),
-            ::boost::forward<T1>(v1)
+            std::forward<T1>(v1)
        );
    }

@@ -1,143 +0,0 @@
-//  Boost.Varaint
-//  Contains multivisitors that are implemented via preprocessor magic
-//
-//  See http://www.boost.org for most recent version, including documentation.
-//
-//  Copyright Antony Polukhin, 2013-2014.
-//
-//  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).
-
-#ifndef BOOST_VARIANT_DETAIL_MULTIVISITORS_PREPROCESSOR_BASED_HPP
-#define BOOST_VARIANT_DETAIL_MULTIVISITORS_PREPROCESSOR_BASED_HPP
-
-#if defined(_MSC_VER)
-# pragma once
-#endif
-
-#include <boost/variant.hpp>
-#include <boost/bind.hpp>
-
-#include <boost/preprocessor/repetition.hpp>
-#include <boost/preprocessor/punctuation/comma_if.hpp>
-#include <boost/preprocessor/arithmetic/add.hpp>
-#include <boost/preprocessor/arithmetic/sub.hpp>
-
-#ifndef BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS
-#   define BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS 4
-#endif
-
-namespace boost { 
-
-namespace detail { namespace variant {
-
-    template <class VisitorT, class Visitable1T, class Visitable2T>
-    struct two_variables_holder {
-    private:
-        VisitorT&       visitor_;
-        Visitable1T&    visitable1_;
-        Visitable2T&    visitable2_;
-
-        // required to suppress warnings and ensure that we do not copy
-        // this visitor
-        two_variables_holder& operator=(const two_variables_holder&);
-
-    public:
-        typedef BOOST_DEDUCED_TYPENAME VisitorT::result_type result_type;
-
-        explicit two_variables_holder(VisitorT& visitor, Visitable1T& visitable1, Visitable2T& visitable2) BOOST_NOEXCEPT 
-            : visitor_(visitor)
-            , visitable1_(visitable1)
-            , visitable2_(visitable2)
-        {}
-
-#define BOOST_VARIANT_OPERATOR_BEG()                            \
-    return ::boost::apply_visitor(                              \
-    ::boost::bind<result_type>(boost::ref(visitor_), _1, _2     \
-    /**/
-
-#define BOOST_VARIANT_OPERATOR_END()                            \
-    ), visitable1_, visitable2_);                               \
-    /**/
-
-#define BOOST_VARANT_VISITORS_VARIABLES_PRINTER(z, n, data)     \
-    BOOST_PP_COMMA() boost::ref( BOOST_PP_CAT(vis, n) )         \
-    /**/
-
-#define BOOST_VARIANT_VISIT(z, n, data)                                                     \
-    template <BOOST_PP_ENUM_PARAMS(BOOST_PP_ADD(n, 1), class VisitableUnwrapped)>           \
-    result_type operator()(                                                                 \
-        BOOST_PP_ENUM_BINARY_PARAMS(BOOST_PP_ADD(n, 1), VisitableUnwrapped, & vis)          \
-    ) const                                                                                 \
-    {                                                                                       \
-        BOOST_VARIANT_OPERATOR_BEG()                                                        \
-        BOOST_PP_REPEAT(BOOST_PP_ADD(n, 1), BOOST_VARANT_VISITORS_VARIABLES_PRINTER, ~)     \
-        BOOST_VARIANT_OPERATOR_END()                                                        \
-    }                                                                                       \
-    /**/
-
-BOOST_PP_REPEAT( BOOST_PP_SUB(BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS, 2), BOOST_VARIANT_VISIT, ~)
-#undef BOOST_VARIANT_OPERATOR_BEG
-#undef BOOST_VARIANT_OPERATOR_END
-#undef BOOST_VARANT_VISITORS_VARIABLES_PRINTER
-#undef BOOST_VARIANT_VISIT
-
-    };
-
-    template <class VisitorT, class Visitable1T, class Visitable2T>
-    inline two_variables_holder<VisitorT, Visitable1T, Visitable2T> make_two_variables_holder(
-            VisitorT& visitor, Visitable1T& visitable1, Visitable2T& visitable2
-        ) BOOST_NOEXCEPT
-    {
-        return two_variables_holder<VisitorT, Visitable1T, Visitable2T>(visitor, visitable1, visitable2);
-    }
-
-    template <class VisitorT, class Visitable1T, class Visitable2T>
-    inline two_variables_holder<const VisitorT, Visitable1T, Visitable2T> make_two_variables_holder(
-            const VisitorT& visitor, Visitable1T& visitable1, Visitable2T& visitable2
-        ) BOOST_NOEXCEPT
-    {
-        return two_variables_holder<const VisitorT, Visitable1T, Visitable2T>(visitor, visitable1, visitable2);
-    }
-
-}} // namespace detail::variant
-
-#define BOOST_VARIANT_APPLY_VISITOR_BEG()                                               \
-    return ::boost::apply_visitor(                                                      \
-            boost::detail::variant::make_two_variables_holder(visitor, var0 , var1),    \
-            var2                                                                        \
-    /**/
-
-#define BOOST_VARIANT_APPLY_VISITOR_END()                       \
-    );                                                          \
-    /**/
-
-#define BOOST_VARANT_VISITORS_VARIABLES_PRINTER(z, n, data)     \
-    BOOST_PP_COMMA() BOOST_PP_CAT(var, BOOST_PP_ADD(n, 3))      \
-    /**/
-
-#define BOOST_VARIANT_VISIT(z, n, data)                                                                 \
-    template <class Visitor BOOST_PP_COMMA() BOOST_PP_ENUM_PARAMS(BOOST_PP_ADD(n, 3), class T)>         \
-    inline BOOST_DEDUCED_TYPENAME Visitor::result_type apply_visitor(                                   \
-        data BOOST_PP_COMMA() BOOST_PP_ENUM_BINARY_PARAMS(BOOST_PP_ADD(n, 3), T, & var)     \
-    )                                                                                                   \
-    {                                                                                                   \
-        BOOST_VARIANT_APPLY_VISITOR_BEG()                                                               \
-        BOOST_PP_REPEAT(n, BOOST_VARANT_VISITORS_VARIABLES_PRINTER, ~)                                  \
-        BOOST_VARIANT_APPLY_VISITOR_END()                                                               \
-    }                                                                                                   \
-    /**/
-
-BOOST_PP_REPEAT( BOOST_PP_SUB(BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS, 2), BOOST_VARIANT_VISIT, const Visitor& visitor)
-BOOST_PP_REPEAT( BOOST_PP_SUB(BOOST_VARAINT_MAX_MULTIVIZITOR_PARAMS, 2), BOOST_VARIANT_VISIT, Visitor& visitor)
-
-#undef BOOST_VARIANT_APPLY_VISITOR_BEG
-#undef BOOST_VARIANT_APPLY_VISITOR_END
-#undef BOOST_VARANT_VISITORS_VARIABLES_PRINTER
-#undef BOOST_VARIANT_VISIT
-    
-} // namespace boost
-
-#endif // BOOST_VARIANT_DETAIL_MULTIVISITORS_PREPROCESSOR_BASED_HPP
-
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2018-2023 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -1,8 +1,3 @@
-
-#if !defined(BOOST_PP_IS_ITERATING)
-
-///// header body
-
 //-----------------------------------------------------------------------------
 // boost variant/detail/substitute.hpp header file
 // See http://www.boost.org for updates, documentation, and revision history.
@@ -21,22 +16,17 @@
 #include <boost/mpl/aux_/config/ctps.hpp>

 #include <boost/variant/detail/substitute_fwd.hpp>
-#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+#include <boost/variant/variant_fwd.hpp>
 #include <boost/mpl/aux_/lambda_arity_param.hpp>
 #include <boost/mpl/aux_/preprocessor/params.hpp>
 #include <boost/mpl/aux_/preprocessor/repeat.hpp>
 #include <boost/mpl/int_fwd.hpp>
 #include <boost/mpl/limits/arity.hpp>
-#include <boost/preprocessor/cat.hpp>
 #include <boost/preprocessor/empty.hpp>
-#include <boost/preprocessor/arithmetic/inc.hpp>
-#include <boost/preprocessor/iterate.hpp>

 namespace boost {
 namespace detail { namespace variant {

-#if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction substitute
 //
@@ -126,7 +116,6 @@ struct substitute<
 // template expression (i.e., F<...>) specializations
 //

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
 template <
      template <typename...> class F
    , typename... Ts
@@ -170,110 +159,8 @@ public:
          A, Dest, Source
        >::type...);
 };
-#else
-
-#define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL(N) \
-    typedef typename substitute< \
-          BOOST_PP_CAT(U,N), Dest, Source \
-        >::type BOOST_PP_CAT(u,N); \
-    /**/
-
-#define BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF(z, N, _) \
-    BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL( BOOST_PP_INC(N) ) \
-    /**/
-
-#define BOOST_PP_ITERATION_LIMITS (0,BOOST_MPL_LIMIT_METAFUNCTION_ARITY)
-#define BOOST_PP_FILENAME_1 <boost/variant/detail/substitute.hpp>
-#include BOOST_PP_ITERATE()
-
-#undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF_IMPL
-#undef BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF
-
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-#endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)

 }} // namespace detail::variant
 } // namespace boost

 #endif // BOOST_VARIANT_DETAIL_SUBSTITUTE_HPP
-
-///// iteration, depth == 1
-
-#elif BOOST_PP_ITERATION_DEPTH() == 1
-#define i BOOST_PP_FRAME_ITERATION(1)
-
-#if i > 0
-
-//
-// template specializations
-//
-template <
-      template < BOOST_MPL_PP_PARAMS(i,typename P) > class T
-    , BOOST_MPL_PP_PARAMS(i,typename U)
-    , typename Dest
-    , typename Source
-    >
-struct substitute<
-      T< BOOST_MPL_PP_PARAMS(i,U) >
-    , Dest
-    , Source
-      BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<( i )>)
-    >
-{
-private:
-    BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
-
-public:
-    typedef T< BOOST_MPL_PP_PARAMS(i,u) > type;
-};
-
-//
-// function specializations
-//
-template <
-      typename R
-    , BOOST_MPL_PP_PARAMS(i,typename U)
-    , typename Dest
-    , typename Source
-    >
-struct substitute<
-      R (*)( BOOST_MPL_PP_PARAMS(i,U) )
-    , Dest
-    , Source
-      BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
-    >
-{
-private:
-    typedef typename substitute< R, Dest, Source >::type r;
-    BOOST_MPL_PP_REPEAT(i, BOOST_VARIANT_AUX_SUBSTITUTE_TYPEDEF, _)
-
-public:
-    typedef r (*type)( BOOST_MPL_PP_PARAMS(i,u) );
-};
-
-#elif i == 0
-
-//
-// zero-arg function specialization
-//
-template <
-      typename R, typename Dest, typename Source
-    >
-struct substitute<
-      R (*)( void )
-    , Dest
-    , Source
-      BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(mpl::int_<-1>)
-    >
-{
-private:
-    typedef typename substitute< R, Dest, Source >::type r;
-
-public:
-    typedef r (*type)( void );
-};
-
-#endif // i
-
-#undef i
-#endif // BOOST_PP_IS_ITERATING
@@ -18,25 +18,12 @@
 #include <boost/mpl/int_fwd.hpp>


-///////////////////////////////////////////////////////////////////////////////
-// BOOST_VARIANT_DETAIL_NO_SUBSTITUTE
-//
-// Defined if 'substitute' is not implementable on the current compiler.
-//
-
 #include <boost/mpl/aux_/config/ctps.hpp>
 #include <boost/mpl/aux_/config/ttp.hpp>

-#if defined(BOOST_NO_TEMPLATE_TEMPLATE_PARAMETERS) \
- && !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-#   define BOOST_VARIANT_DETAIL_NO_SUBSTITUTE
-#endif
-
 namespace boost {
 namespace detail { namespace variant {

-#if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 ///////////////////////////////////////////////////////////////////////////////
 // metafunction substitute
 //
@@ -50,8 +37,6 @@ template <
    >
 struct substitute;

-#endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 }} // namespace detail::variant
 } // namespace boost

@@ -16,8 +16,6 @@
 #include <iosfwd> // for std::basic_ostream forward declare

 #include <boost/variant/variant_fwd.hpp>
-
-#include <boost/detail/templated_streams.hpp>
 #include <boost/variant/static_visitor.hpp>

 namespace boost {
@@ -29,14 +27,9 @@ namespace boost {
 //

 // forward declare (allows output of embedded variant< variant< ... >, ... >)
-template <
-      BOOST_TEMPLATED_STREAM_ARGS(E,T)
-    BOOST_TEMPLATED_STREAM_COMMA
-      BOOST_VARIANT_ENUM_PARAMS(typename U)
-    >
-inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(
-      BOOST_TEMPLATED_STREAM(ostream, E,T)& out
-    , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs
+template <class CharT, class Trait, typename... U>
+inline std::basic_ostream<CharT, Trait>& operator<<(
+      std::basic_ostream<CharT, Trait>& out, const variant<U...>& rhs
    );

 namespace detail { namespace variant {
@@ -71,18 +64,13 @@ private:

 }} // namespace detail::variant

-template <
-      BOOST_TEMPLATED_STREAM_ARGS(E,T)
-    BOOST_TEMPLATED_STREAM_COMMA
-      BOOST_VARIANT_ENUM_PARAMS(typename U)
-    >
-inline BOOST_TEMPLATED_STREAM(ostream, E,T)& operator<<(
-      BOOST_TEMPLATED_STREAM(ostream, E,T)& out
-    , const variant< BOOST_VARIANT_ENUM_PARAMS(U) >& rhs
+template <class CharT, class Trait, typename... U>
+inline std::basic_ostream<CharT, Trait>& operator<<(
+      std::basic_ostream<CharT, Trait>& out, const variant<U...>& rhs
    )
 {
    detail::variant::printer<
-          BOOST_TEMPLATED_STREAM(ostream, E,T)
+          std::basic_ostream<CharT, Trait>
        > visitor(out);

    rhs.apply_visitor(visitor);
@@ -18,7 +18,7 @@
 #include <boost/variant/detail/backup_holder.hpp>
 #include <boost/variant/detail/cast_storage.hpp>
 #include <boost/variant/detail/forced_return.hpp>
-#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+#include <boost/variant/variant_fwd.hpp>

 #include <boost/mpl/eval_if.hpp>
 #include <boost/mpl/bool.hpp>
@@ -47,24 +47,12 @@
 //
 #if !defined(BOOST_VARIANT_VISITATION_UNROLLING_LIMIT)

-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
 #   include <boost/mpl/limits/list.hpp>
 #   define BOOST_VARIANT_VISITATION_UNROLLING_LIMIT   \
        BOOST_MPL_LIMIT_LIST_SIZE
-#else
-#   define BOOST_VARIANT_VISITATION_UNROLLING_LIMIT   \
-        BOOST_VARIANT_LIMIT_TYPES
-#endif

 #endif

-// Define a compiler generic null pointer value
-#if defined(BOOST_NO_CXX11_NULLPTR)
-#define BOOST_VARIANT_NULL 0
-#else
-#define BOOST_VARIANT_NULL nullptr
-#endif
-
 namespace boost {
 namespace detail { namespace variant {

@@ -184,7 +172,7 @@ inline typename Visitor::result_type
 visitation_impl(
      int, int, Visitor&, VPCV
    , mpl::true_ // is_apply_visitor_unrolled
-    , NBF, W* = BOOST_VARIANT_NULL, S* = BOOST_VARIANT_NULL
+    , NBF, W* = nullptr, S* = nullptr
    )
 {
    // should never be here at runtime!
@@ -203,7 +191,7 @@ visitation_impl(
    , Visitor& visitor, VoidPtrCV storage
    , mpl::false_ // is_apply_visitor_unrolled
    , NoBackupFlag no_backup_flag
-    , Which* = BOOST_VARIANT_NULL, step0* = BOOST_VARIANT_NULL
+    , Which* = nullptr, step0* = nullptr
    )
 {
    // Typedef apply_visitor_unrolled steps and associated types...
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman, Itay Maman
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 //
 //  See http://www.boost.org for most recent version, including documentation.
 //
-//  Copyright (c) 2013-2023 Antony Polukhin.
+//  Copyright (c) 2013-2026 Antony Polukhin.
 //
 //  Distributed under the Boost
 //  Software License, Version 1.0. (See accompanying file
@@ -17,15 +17,11 @@
 #endif

 #include <boost/config.hpp>
-#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+#include <boost/variant/variant_fwd.hpp>

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
-#   include <boost/variant/detail/multivisitors_cpp11_based.hpp>
-#   if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
-#       include <boost/variant/detail/multivisitors_cpp14_based.hpp>
-#   endif
-#else
-#   include <boost/variant/detail/multivisitors_preprocessor_based.hpp>
+#include <boost/variant/detail/multivisitors_cpp11_based.hpp>
+#if !defined(BOOST_NO_CXX14_DECLTYPE_AUTO) && !defined(BOOST_NO_CXX11_DECLTYPE_N3276)
+#   include <boost/variant/detail/multivisitors_cpp14_based.hpp>
 #endif

 #endif // BOOST_VARIANT_MULTIVISITORS_HPP
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -45,8 +45,6 @@ namespace detail { namespace variant {
 // Handles embedded variant types when substituting for recursive_variant_.
 //

-#if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 template <
      BOOST_VARIANT_ENUM_PARAMS(typename T)
    , typename RecursiveVariant
@@ -115,9 +113,7 @@ struct substitute<
    , ::boost::recursive_variant_
      BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(Arity)
    >
-{
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-    
+{   
    typedef ::boost::variant<
        typename enable_recursive<   
              T0              
@@ -130,41 +126,8 @@ struct substitute<
            , mpl::true_                     
        >::type...  
    > type;
-
-#else // defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
-private: // helpers, for metafunction result (below)
-
-    #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_)  \
-        typedef typename enable_recursive<   \
-              BOOST_PP_CAT(T,N)              \
-            , RecursiveVariant               \
-            , mpl::true_                     \
-            >::type BOOST_PP_CAT(wknd_T,N);  \
-        /**/
-
-    BOOST_PP_REPEAT(
-          BOOST_VARIANT_LIMIT_TYPES
-        , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
-        , _
-        )
-
-    #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
-
-public: // metafunction result
-
-    typedef ::boost::variant< BOOST_VARIANT_ENUM_PARAMS(wknd_T) > type;
-#endif // BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES workaround
 };

-#else // defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
-//
-// no specializations: embedded variants unsupported on these compilers!
-//
-
-#endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
-
 }} // namespace detail::variant

 ///////////////////////////////////////////////////////////////////////////////
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2002 Eric Friedman, Itay Maman
-// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // Portions Copyright (C) 2002 David Abrahams
 //
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2002-2003 Eric Friedman, Itay Maman
-// Copyright (c) 2012-2023 Antony Polukhin
+// Copyright (c) 2012-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -40,8 +40,6 @@
 #include <boost/blank.hpp>
 #include <boost/integer/common_factor_ct.hpp>
 #include <boost/static_assert.hpp>
-#include <boost/preprocessor/cat.hpp>
-#include <boost/preprocessor/repeat.hpp>
 #include <boost/type_traits/aligned_storage.hpp>
 #include <boost/type_traits/alignment_of.hpp>
 #include <boost/type_traits/add_const.hpp>
@@ -221,7 +219,6 @@ public: // metafunction result

 };

-#ifndef BOOST_NO_CXX11_NOEXCEPT
 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction is_variant_move_noexcept_constructible
 //
@@ -255,7 +252,6 @@ struct is_variant_move_noexcept_assignable {
        iterator_t, end_t
    >::type type;
 };
-#endif // BOOST_NO_CXX11_NOEXCEPT

 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction is_variant_constructible_from
@@ -308,8 +304,6 @@ struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T
    is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types >
 {};

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-
 template <BOOST_VARIANT_ENUM_PARAMS(typename T), class Types>
 struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>&& , Types >:
    is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types >
@@ -320,8 +314,6 @@ struct is_variant_constructible_from< boost::variant<BOOST_VARIANT_ENUM_PARAMS(T
    is_variant_constructible_from<boost::variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Types >
 {};

-#endif // #ifndef BOOST_NO_CXX11_RVALUE_REFERENCE
-

 ///////////////////////////////////////////////////////////////////////////////
 // (detail) metafunction make_storage
@@ -466,7 +458,6 @@ public: // internal visitor interface
 //
 // Internal visitor that moves the value it visits into the given buffer.
 //
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
 class move_into
    : public static_visitor<>
 {
@@ -495,7 +486,6 @@ public: // internal visitor interface
        new(storage_) T(::boost::detail::variant::move(operand));
    }
 };
-#endif

 ///////////////////////////////////////////////////////////////////////////////
 // (detail) class assign_storage
@@ -1012,13 +1002,11 @@ public: // structors

 public: // internal visitor interfaces

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-
    //using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work
    template <typename T>
    typename enable_if_c<MoveSemantics && is_same<T, T>::value, result_type>::type internal_visit(T&& operand, int)
    {
-        return visitor_(::boost::move(operand));
+        return visitor_(std::move(operand));
    }

    //using workaround with is_same<T, T> to prenvent compilation error, because we need to use T in enable_if to make SFINAE work
@@ -1028,24 +1016,6 @@ public: // internal visitor interfaces
        return visitor_(operand);
    }

-#else
-
-    template <typename T>
-    result_type internal_visit(T& operand, int)
-    {
-        return visitor_(operand);
-    }
-
-#   if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x0564))
-    template <typename T>
-    result_type internal_visit(const T& operand, int)
-    {
-        return visitor_(operand);
-    }
-#   endif //BORLAND
-
-#endif //RVALUE REFERENCES
-
 public: // internal visitor interfaces, cont.

    template <typename T>
@@ -1124,8 +1094,6 @@ private: // helpers, for typedefs (below)
    {
    };

-#if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
-
 private: // helpers, for typedefs (below)

    typedef typename mpl::eval_if<
@@ -1169,82 +1137,6 @@ private: // internal typedefs
          internal_types
        >::type internal_T0;

-#else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
-
-private: // helpers, for typedefs (below)
-
-    typedef unwrapped_T0_ T0;
-
-    #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_) \
-        typedef typename mpl::eval_if< \
-              is_recursive_ \
-            , detail::variant::enable_recursive< \
-                  BOOST_PP_CAT(T,N) \
-                , wknd_self_t \
-                > \
-            , mpl::identity< BOOST_PP_CAT(T,N) > \
-            >::type BOOST_PP_CAT(recursive_enabled_T,N); \
-        /**/
-
-    BOOST_PP_REPEAT(
-          BOOST_VARIANT_LIMIT_TYPES
-        , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
-        , _
-        )
-
-    #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
-
-    #define BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS(z,N,_) \
-        typedef typename unwrap_recursive< \
-              BOOST_PP_CAT(recursive_enabled_T,N) \
-            >::type BOOST_PP_CAT(public_T,N); \
-        /**/
-
-    BOOST_PP_REPEAT(
-          BOOST_VARIANT_LIMIT_TYPES
-        , BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
-        , _
-        )
-
-    #undef BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
-
-public: // public typedefs
-
-    typedef typename detail::variant::make_variant_list<
-          BOOST_VARIANT_ENUM_PARAMS(public_T)
-        >::type types;
-
-private: // helpers, for internal typedefs (below)
-
-    #define BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS(z,N,_) \
-        typedef detail::make_reference_content< \
-              BOOST_PP_CAT(recursive_enabled_T,N) \
-            >::type BOOST_PP_CAT(internal_T,N); \
-        /**/
-
-    BOOST_PP_REPEAT(
-          BOOST_VARIANT_LIMIT_TYPES
-        , BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
-        , _
-        )
-
-    #undef BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
-
-private: // internal typedefs
-
-    typedef typename detail::variant::make_variant_list<
-          BOOST_VARIANT_ENUM_PARAMS(internal_T)
-        >::type internal_types;
-
-private: // static precondition assertions
-
-    // NOTE TO USER :
-    // variant< type-sequence > syntax is not supported on this compiler!
-    //
-    BOOST_MPL_ASSERT_NOT(( is_sequence_based_ ));
-
-#endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround
-
 private: // helpers, for representation (below)

    typedef typename detail::variant::find_fallback_type<
@@ -1270,7 +1162,6 @@ private: // helpers, for representation (below)
          internal_types, never_uses_backup_flag
        >::type storage_t;

-#ifndef BOOST_NO_CXX11_NOEXCEPT
    typedef typename detail::variant::is_variant_move_noexcept_constructible<
        internal_types
    > variant_move_noexcept_constructible;
@@ -1279,8 +1170,6 @@ private: // helpers, for representation (below)
        internal_types
    > variant_move_noexcept_assignable;

-#endif
-
 private: // helpers, for representation (below)

    // which_ on:
@@ -1471,7 +1360,6 @@ private: // helpers, for structors, cont. (below)

    friend class convert_copy_into;

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    class convert_move_into
        : public static_visitor<int>
    {
@@ -1537,7 +1425,6 @@ private: // helpers, for structors, cont. (below)
    };

    friend class convert_move_into;
-#endif

 private: // helpers, for structors, below

@@ -1561,7 +1448,6 @@ private: // helpers, for structors, below
            );
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <typename T>
    typename boost::enable_if<boost::is_rvalue_reference<T&&> >::type convert_construct(
          T&& operand
@@ -1581,7 +1467,6 @@ private: // helpers, for structors, below
                )
            );
    }
-#endif

    template <typename Variant>
    void convert_construct(
@@ -1596,7 +1481,6 @@ private: // helpers, for structors, below
            );
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <typename Variant>
    typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct(
          Variant&& operand
@@ -1609,7 +1493,6 @@ private: // helpers, for structors, below
              operand.internal_apply_visitor(visitor)
            );
    }
-#endif

    template <typename Variant>
    void convert_construct_variant(Variant& operand)
@@ -1638,7 +1521,6 @@ private: // helpers, for structors, below
            );
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <typename Variant>
    typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct_variant(Variant&& operand)
    {
@@ -1665,7 +1547,6 @@ private: // helpers, for structors, below
            , is_foreign_variant()
            );
    }
-#endif

    template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
    typename boost::enable_if<mpl::or_<
@@ -1691,7 +1572,6 @@ private: // helpers, for structors, below
        convert_construct_variant(operand);
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
    typename boost::enable_if<mpl::or_<
        boost::is_same<boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>, variant>,
@@ -1703,7 +1583,6 @@ private: // helpers, for structors, below
    {
        convert_construct_variant( detail::variant::move(operand) );
    }
-#endif

 public: // structors, cont.

@@ -1736,7 +1615,6 @@ public: // structors, cont.
        convert_construct(operand, 1L);
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <class T>
    variant(T&& operand,
        typename boost::enable_if<mpl::or_<
@@ -1751,7 +1629,6 @@ public: // structors, cont.
    {
        convert_construct( detail::variant::move(operand), 1L);
    }
-#endif

 public: // structors, cont.

@@ -1766,7 +1643,6 @@ public: // structors, cont.
        indicate_which(operand.which());
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    variant(variant&& operand) BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value)
    {
        // Move the value of operand into *this...
@@ -1776,14 +1652,11 @@ public: // structors, cont.
        // ...and activate the *this's primary storage on success:
        indicate_which(operand.which());
    }
-#endif

 private: // helpers, for modifiers (below)

-#   if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
    template <typename Variant>
    friend class detail::variant::backup_assigner;
-#   endif

    // class assigner
    //
@@ -1933,7 +1806,6 @@ private: // helpers, for modifiers (below)

    friend class assigner;

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    // class move_assigner
    //
    // Internal visitor that "move assigns" the visited value to the given variant
@@ -2051,7 +1923,6 @@ private: // helpers, for modifiers (below)
    };

    friend class move_assigner;
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES

    void variant_assign(const variant& rhs)
    {
@@ -2070,7 +1941,6 @@ private: // helpers, for modifiers (below)
        }
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    void variant_assign(variant&& rhs)
    {
        // If the contained types are EXACTLY the same...
@@ -2087,7 +1957,6 @@ private: // helpers, for modifiers (below)
            rhs.internal_apply_visitor(visitor);
        }
    }
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES

 private: // helpers, for modifiers (below)

@@ -2109,7 +1978,6 @@ private: // helpers, for modifiers (below)
        }
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <typename T>
    void move_assign(T&& rhs)
    {
@@ -2127,12 +1995,10 @@ private: // helpers, for modifiers (below)
            variant_assign( detail::variant::move(temp) );
        }
    }
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES

 public: // modifiers

-#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
-    (!BOOST_WORKAROUND(BOOST_CLANG_VERSION, BOOST_TESTED_AT(150000)) || BOOST_CXX_VERSION <= 202002L)
+#if !BOOST_WORKAROUND(BOOST_CLANG_VERSION, BOOST_TESTED_AT(150000)) || BOOST_CXX_VERSION <= 202002L
    template <class T>
    typename boost::enable_if<
        boost::mpl::and_<
@@ -2146,7 +2012,7 @@ public: // modifiers
        move_assign( detail::variant::move(rhs) );
        return *this;
    }
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES
+#endif

    template <typename T>
    typename boost::enable_if<
@@ -2168,7 +2034,6 @@ public: // modifiers
        return *this;
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    variant& operator=(variant&& rhs)
 #if !defined(__GNUC__) || (__GNUC__ != 4) || (__GNUC_MINOR__ > 6) || defined(__clang__)
        BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value && variant_move_noexcept_assignable::type::value)
@@ -2177,7 +2042,6 @@ public: // modifiers
        variant_assign( detail::variant::move(rhs) );
        return *this;
    }
-#endif // BOOST_NO_CXX11_RVALUE_REFERENCES

    void swap(variant& rhs)
    {
@@ -2363,8 +2227,6 @@ public:

 public: // visitation support

-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
-
    template <typename Visitor>
    typename Visitor::result_type
    apply_visitor(Visitor& visitor) &&
@@ -2381,14 +2243,9 @@ public: // visitation support
        return this->internal_apply_visitor(invoker);
    }

-#endif
-
    template <typename Visitor>
    typename Visitor::result_type
-    apply_visitor(Visitor& visitor)
-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
-    &
-#endif
+    apply_visitor(Visitor& visitor) &
    {
        detail::variant::invoke_visitor<Visitor, false> invoker(visitor);
        return this->internal_apply_visitor(invoker);
@@ -2396,10 +2253,7 @@ public: // visitation support

    template <typename Visitor>
    typename Visitor::result_type
-    apply_visitor(Visitor& visitor) const
-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
-    &
-#endif
+    apply_visitor(Visitor& visitor) const &
    {
        detail::variant::invoke_visitor<Visitor, false> invoker(visitor);
        return this->internal_apply_visitor(invoker);
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman, Itay Maman
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -25,15 +25,6 @@
 #include <boost/preprocessor/enum_shifted_params.hpp>
 #include <boost/preprocessor/repeat.hpp>

-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT
-//
-// Defined if variant does not support make_variant_over (see below). 
-//
-#if defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-#   define BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT
-#endif
-
 ///////////////////////////////////////////////////////////////////////////////
 // macro BOOST_VARIANT_NO_FULL_RECURSIVE_VARIANT_SUPPORT
 //
@@ -45,37 +36,6 @@

 #include <boost/variant/detail/substitute_fwd.hpp>

-#if defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE) \
-  && !defined(BOOST_VARIANT_NO_FULL_RECURSIVE_VARIANT_SUPPORT)
-#   define BOOST_VARIANT_NO_FULL_RECURSIVE_VARIANT_SUPPORT
-#endif
-
-
-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-//
-
-/* 
-    GCC before 4.0 had no variadic tempaltes; 
-    GCC 4.6 has incomplete implementation of variadic templates.
-
-    MSVC2015 Update 1 has variadic templates, but they have issues.
-
-    NOTE: Clang compiler defines __GNUC__
-*/
-#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) \
-  || (!defined(__clang__) && defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ < 7)) \
-  || (defined(_MSC_VER) && (_MSC_VER <= 1900)) \
-  || defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE) \
-  || defined (BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
-
-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-#   define BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-#endif
-
-#endif
-
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
 #include <boost/preprocessor/seq/size.hpp>

 #define BOOST_VARIANT_CLASS_OR_TYPENAME_TO_SEQ_class class)(
@@ -108,9 +68,6 @@
 // Rationale: Cleaner, simpler code for clients of variant library. Minimal 
 // code modifications to move from C++03 to C++11.
 //
-// With BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES defined
-// will be used BOOST_VARIANT_ENUM_PARAMS and BOOST_VARIANT_ENUM_SHIFTED_PARAMS from below `#else`
-//

 #define BOOST_VARIANT_ENUM_PARAMS(x) \
    x ## 0, \
@@ -121,49 +78,6 @@
    BOOST_VARIANT_MAKE_VARIADIC( (BOOST_VARIANT_CLASS_OR_TYPENAME_TO_SEQ_ ## x), x) \
    /**/

-#else // defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_LIMIT_TYPES
-//
-// Implementation-defined preprocessor symbol describing the actual
-// length of variant's pseudo-variadic template parameter list.
-//
-#include <boost/mpl/limits/list.hpp>
-#define BOOST_VARIANT_LIMIT_TYPES \
-    BOOST_MPL_LIMIT_LIST_SIZE
-
-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_RECURSIVE_VARIANT_MAX_ARITY
-//
-// Exposes maximum allowed arity of class templates with recursive_variant
-// arguments. That is,
-//   make_recursive_variant< ..., T<[1], recursive_variant_, ... [N]> >.
-//
-#include <boost/mpl/limits/arity.hpp>
-#define BOOST_VARIANT_RECURSIVE_VARIANT_MAX_ARITY \
-    BOOST_MPL_LIMIT_METAFUNCTION_ARITY
-
-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_ENUM_PARAMS
-//
-// Convenience macro for enumeration of BOOST_VARIANT_LIMIT_TYPES params.
-//
-// Rationale: Cleaner, simpler code for clients of variant library.
-//
-#define BOOST_VARIANT_ENUM_PARAMS( param )  \
-    BOOST_PP_ENUM_PARAMS(BOOST_VARIANT_LIMIT_TYPES, param)
-
-///////////////////////////////////////////////////////////////////////////////
-// macro BOOST_VARIANT_ENUM_SHIFTED_PARAMS
-//
-// Convenience macro for enumeration of BOOST_VARIANT_LIMIT_TYPES-1 params.
-//
-#define BOOST_VARIANT_ENUM_SHIFTED_PARAMS( param )  \
-    BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_VARIANT_LIMIT_TYPES, param)
-
-#endif // BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES workaround
-

 namespace boost {

@@ -195,75 +109,9 @@ struct convert_void< void_ >
    typedef mpl::na type;
 };

-///////////////////////////////////////////////////////////////////////////////
-// (workaround) BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE
-//
-// Needed to work around compilers that don't support using-declaration
-// overloads. (See the variant::initializer workarounds below.)
-//
-
-#if defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-// (detail) tags voidNN -- NN defined on [0, BOOST_VARIANT_LIMIT_TYPES)
-//
-// Defines void types that are each unique and specializations of
-// convert_void that yields mpl::na for each voidNN type.
-//
-
-#define BOOST_VARIANT_DETAIL_DEFINE_VOID_N(z,N,_)          \
-    struct BOOST_PP_CAT(void,N);                           \
-                                                           \
-    template <>                                            \
-    struct convert_void< BOOST_PP_CAT(void,N) >            \
-    {                                                      \
-        typedef mpl::na type;                              \
-    };                                                     \
-    /**/
-
-BOOST_PP_REPEAT(
-      BOOST_VARIANT_LIMIT_TYPES
-    , BOOST_VARIANT_DETAIL_DEFINE_VOID_N
-    , _
-    )
-
-#undef BOOST_VARIANT_DETAIL_DEFINE_VOID_N
-
-#endif // BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE workaround
-
 }} // namespace detail::variant

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-#   define BOOST_VARIANT_AUX_DECLARE_PARAMS BOOST_VARIANT_ENUM_PARAMS(typename T)
-#else // defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
-///////////////////////////////////////////////////////////////////////////////
-// (detail) macro BOOST_VARIANT_AUX_DECLARE_PARAM
-//
-// Template parameter list for variant and recursive_variant declarations.
-//
-
-#if !defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
-#   define BOOST_VARIANT_AUX_DECLARE_PARAMS_IMPL(z, N, T) \
-    typename BOOST_PP_CAT(T,N) = detail::variant::void_ \
-    /**/
-
-#else // defined(BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE)
-
-#   define BOOST_VARIANT_AUX_DECLARE_PARAMS_IMPL(z, N, T) \
-    typename BOOST_PP_CAT(T,N) = BOOST_PP_CAT(detail::variant::void,N) \
-    /**/
-
-#endif // BOOST_NO_USING_DECLARATION_OVERLOADS_FROM_TYPENAME_BASE workaround
-
-#define BOOST_VARIANT_AUX_DECLARE_PARAMS \
-    BOOST_PP_ENUM( \
-          BOOST_VARIANT_LIMIT_TYPES \
-        , BOOST_VARIANT_AUX_DECLARE_PARAMS_IMPL \
-        , T \
-        ) \
-    /**/
-
-#endif // BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES workaround
+#define BOOST_VARIANT_AUX_DECLARE_PARAMS BOOST_VARIANT_ENUM_PARAMS(typename T)

 ///////////////////////////////////////////////////////////////////////////////
 // class template variant (concept inspired by Andrei Alexandrescu)
@@ -1,6 +1,6 @@
 <!DOCTYPE html>
 <!--
- Copyright 2014-2023 Antony Polukhin
+ Copyright 2014-2026 Antony Polukhin
 antoshkka at gmail dot com

 Distributed under the Boost Software License,
@@ -29,7 +29,7 @@
    <a href="../../doc/html/variant.html">../../doc/html/variant.html</a>
  </p>
  <p>
-    &copy; 2014-2023 Antony Polukhin
+    &copy; 2014-2024 Antony Polukhin
  </p>
 </body>
 </html>
@@ -14,5 +14,5 @@
        "Antony Polukhin <antoshkka -at- gmail.com>",
        "Eric Friedman <ericbrandon -at- gmail.com>"
    ],
-    "cxxstd": "03"
+    "cxxstd": "11"
 }
@@ -1,5 +1,5 @@
 #==============================================================================
-#   Copyright (c) 2012-2023 Antony Polukhin
+#   Copyright (c) 2012-2026 Antony Polukhin
 #
 #   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)
@@ -1,21 +1,25 @@
 #  Boost.Variant Library test Jamfile
 #
 #  Copyright (C) 2003, Eric Friedman, Itay Maman.
-#  Copyright (C) 2013-2023 Antony Polukhin.
+#  Copyright (C) 2013-2026 Antony Polukhin.
 #
 # 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)
 #

+require-b2 5.0.1 ;
+import-search /boost/config/checks ;
+import config : requires ;
 import testing ;

-local below_cpp11 = 98 03 ;
 local below_cpp14 = 98 03 0x 11 ;
 local since_cpp20 = 2a 20 latest ;

 project
    : requirements
+        <library>/boost/variant//boost_variant
+        [ requires cxx11_rvalue_references ]
        <toolset>msvc:<asynch-exceptions>on
    ;
 test-suite variant
@@ -29,7 +33,7 @@ test-suite variant
    [ run test6.cpp : : : : variant_test6 ]
    [ run test7.cpp : : : : variant_test7 ]
    [ run test8.cpp : : : : variant_test8 ]
-    [ run test9.cpp : : : : variant_test9 ]
+    [ run test9.cpp : : : <library>/boost/fusion//boost_fusion : variant_test9 ]
    [ run recursive_variant_test.cpp ]
    [ run variant_reference_test.cpp ]
    [ run variant_comparison_test.cpp ]
@@ -38,7 +42,7 @@ test-suite variant
    [ run variant_get_test.cpp ]
    [ compile-fail variant_rvalue_get_with_ampersand_test.cpp ]
    [ compile-fail no_rvalue_to_nonconst_visitation.cpp ]
-    [ compile fusion_interop.cpp : "<cxxstd>$(below_cpp11)"\:<build>no ]
+    [ compile fusion_interop.cpp : <library>/boost/fusion//boost_fusion ]
    [ run variant_polymorphic_get_test.cpp ]
    [ run variant_multivisit_test.cpp ]
    [ run hash_variant_test.cpp ]
@@ -57,13 +61,13 @@ test-suite variant
    [ run recursive_variant_test.cpp : : : <rtti>off <define>BOOST_NO_RTTI <define>BOOST_NO_TYPEID : variant_no_rtti_test ]
    [ run hash_recursive_variant_test.cpp ]
    [ run variant_swap_test.cpp ]
-    [ run auto_visitors.cpp ]
+    [ run auto_visitors.cpp : : : <library>/boost/lexical_cast//boost_lexical_cast ]
    [ run issue42.cpp ]
-    [ run issue53.cpp ]
+    [ compile issue53.cpp : <library>/boost/thread//boost_thread ]
    [ run overload_selection.cpp : : : "<cxxstd>$(since_cpp20)"\:<build>no ]
-    [ run recursive_wrapper_move_test.cpp ]
+    [ run recursive_wrapper_move_test.cpp : : : <library>/boost/array//boost_array ]
    [ run variant_over_joint_view_test.cpp ]
-    [ run const_ref_apply_visitor.cpp ]
-   ; 
+    [ run const_ref_apply_visitor.cpp : : : <library>/boost/lexical_cast//boost_lexical_cast ]
+   ;


@@ -32,9 +32,6 @@ skip_tags: true

 environment:
  matrix:
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0,msvc-12.0
-      ADDRMD: 32
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
      TOOLSET: msvc-14.1,clang-win
      CXXSTD: 14,17
@@ -48,10 +45,11 @@ environment:
      TOOLSET: gcc
      CXXSTD: 03,11,14,1z
      VARIANT: release          # "variant_get_test.o: File too big" errors in debug
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-      ADDPATH: C:\mingw\bin;
-      TOOLSET: gcc
-      CXXSTD: 03,11,14,1z
+    # MinGW 32-bit is not supported by Boost.System any more
+    # - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    #  ADDPATH: C:\mingw\bin;
+    #  TOOLSET: gcc
+    #  CXXSTD: 03,11,14,1z
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
      ADDPATH: C:\mingw-w64\x86_64-7.2.0-posix-seh-rt_v5-rev1\mingw64\bin;
      TOOLSET: gcc
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -188,12 +188,6 @@ struct lex_streamer2 {
    }
 };

-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-#   define BOOST_TEST_IF_HAS_VARIADIC(x) BOOST_TEST(x)
-#else
-#   define BOOST_TEST_IF_HAS_VARIADIC(x) /**/
-#endif
-
 void run()
 {
    typedef boost::variant<int, std::string, double> variant_type;
@@ -201,9 +195,9 @@ void run()
    lex_streamer lex_streamer_visitor;

    BOOST_TEST(boost::apply_visitor(lex_streamer(), v1) == "1");
-    BOOST_TEST_IF_HAS_VARIADIC(boost::apply_visitor(lex_streamer_visitor)(v1) == "1");
+    BOOST_TEST(boost::apply_visitor(lex_streamer_visitor)(v1) == "1");
    BOOST_TEST(boost::apply_visitor(lex_streamer(), v2) == "10");
-    BOOST_TEST_IF_HAS_VARIADIC(boost::apply_visitor(lex_streamer_visitor)(v2) == "10");
+    BOOST_TEST(boost::apply_visitor(lex_streamer_visitor)(v2) == "10");

    #ifndef BOOST_NO_CXX14_GENERIC_LAMBDAS
        BOOST_TEST(boost::apply_visitor([](auto v) { return boost::lexical_cast<std::string>(v); }, v1) == "1");
@@ -220,16 +214,16 @@ void run()
    lex_streamer2 visitor_ref;
    BOOST_TEST(boost::apply_visitor(visitor_ref, v1) == "1");
    BOOST_TEST(boost::apply_visitor(visitor_ref, v2) == "10");
-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+
    std::string& ref_to_string = boost::apply_visitor(visitor_ref, v1);
    BOOST_TEST(ref_to_string == "1");
-#endif
+
    lex_streamer_void lex_streamer_void_visitor;
    boost::apply_visitor(lex_streamer_void(), v1);
    boost::apply_visitor(lex_streamer_void(), v2);
-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+
    boost::apply_visitor(lex_streamer_void_visitor)(v2);
-#endif
+

    boost::ignore_unused(lex_streamer_visitor, visitor_ref, lex_streamer_void_visitor);
 }
@@ -258,7 +252,7 @@ void run2()

    BOOST_TEST(boost::apply_visitor(lex_combine(), v1, v2) == "1+10");
    BOOST_TEST(boost::apply_visitor(lex_combine(), v2, v1) == "10+1");
-    BOOST_TEST_IF_HAS_VARIADIC(boost::apply_visitor(lex_combine_visitor)(v2, v1) == "10+1");
+    BOOST_TEST(boost::apply_visitor(lex_combine_visitor)(v2, v1) == "10+1");


    #ifndef BOOST_NO_CXX14_GENERIC_LAMBDAS
@@ -291,10 +285,9 @@ void run2()
    lex_streamer2 visitor_ref;
    BOOST_TEST(boost::apply_visitor(visitor_ref, v1, v2) == "1+10");
    BOOST_TEST(boost::apply_visitor(visitor_ref, v2, v1) == "10+1");
-#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
+
    std::string& ref_to_string = boost::apply_visitor(visitor_ref)(v1, v2);
    BOOST_TEST(ref_to_string == "1+10");
-#endif

    boost::apply_visitor(lex_streamer_void(), v1, v2);
    boost::apply_visitor(lex_streamer_void(), v2, v1);
@@ -302,11 +295,8 @@ void run2()
    boost::ignore_unused(lex_combine_visitor, visitor_ref);
 }

-#undef BOOST_TEST_IF_HAS_VARIADIC
-
 void run3()
 {
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    typedef boost::variant<int, std::string, double> variant_type;
    variant_type v1(1), v2("10"), v3(100);
    lex_combine lex_combine_visitor;
@@ -363,7 +353,7 @@ void run3()
    boost::apply_visitor(lex_streamer_void(), v1, v2, v1);
    boost::apply_visitor(lex_streamer_void(), v2, v1, v1);
    boost::apply_visitor(lex_streamer_void_visitor)(v2, v1, v1);
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
+
 }
 #endif

@@ -29,13 +29,11 @@ struct construction_logger
        std::cout << val_ << " copy constructed\n";
    }

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    construction_logger(construction_logger&& cl) :
        val_(cl.val_)
    {
        std::cout << val_ << " move constructed\n";
    }
-#endif

    friend std::ostream& operator << (std::ostream& os, const construction_logger& cl)
    {
@@ -71,7 +69,6 @@ struct lex_streamer_explicit : boost::static_visitor<std::string>

 struct lvalue_rvalue_detector : boost::static_visitor<std::string>
 {
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
    template <class T>
    std::string operator()(T&&) const
    {
@@ -96,31 +93,6 @@ struct lvalue_rvalue_detector : boost::static_visitor<std::string>
    {
        return operator()(std::forward<T>(t), std::forward<V>(v), std::forward<P>(p)) + ", " + operator()(std::forward<S>(s));
    }
-#else
-    template <class T>
-    std::string operator()(T&) const
-    {
-        return "lvalue reference";
-    }
-
-    template <class T, class V>
-    std::string operator()(T&, V&) const
-    {
-        return "lvalue reference, lvalue reference";
-    }
-
-    template <class T, class V, class P>
-    std::string operator()(T&, V&, P&) const
-    {
-        return "lvalue reference, lvalue reference, lvalue reference";
-    }
-
-    template <class T, class V, class P, class S>
-    std::string operator()(T&, V&, P&, S&) const
-    {
-        return "lvalue reference, lvalue reference, lvalue reference, lvalue reference";
-    }
-#endif
 };

 typedef boost::variant<construction_logger, std::string> variant_type;
@@ -147,8 +119,6 @@ void test_const_ref_parameter4(const variant_type& test_var, const variant_type&
            == "lvalue reference, lvalue reference, lvalue reference, lvalue reference");
 }

-#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_NO_CXX11_REF_QUALIFIERS)
-
 void test_rvalue_parameter(variant_type&& test_var)
 {
    std::cout << "Testing rvalue visitable\n";
@@ -166,22 +136,13 @@ void test_rvalue_parameter2(variant_type&& test_var, variant_type&& test_var2)

 void test_rvalue_parameter4(variant_type&& test_var, variant_type&& test_var2, variant_type&& test_var3, variant_type&& test_var4)
 {
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing rvalue visitable with multivisitor\n";

    auto result = boost::apply_visitor(lvalue_rvalue_detector(), std::move(test_var), std::move(test_var2), std::move(test_var3), std::move(test_var4));
    std::cout << "result: " << result << std::endl;
    BOOST_TEST(result == "rvalue reference, rvalue reference, rvalue reference, rvalue reference");
-#else
-    (void)test_var;
-    (void)test_var2;
-    (void)test_var3;
-    (void)test_var4;
-#endif
 }

-#endif
-
 #ifndef BOOST_NO_CXX14_DECLTYPE_AUTO

 #define FORWARD(x) std::forward<decltype(x)>(x)
@@ -210,18 +171,12 @@ void test_cpp14_visitor(const variant_type& test_var, const variant_type& test_v

 void test_cpp14_visitor(const variant_type& test_var, const variant_type& test_var2, const variant_type& test_var3)
 {
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing const lvalue visitable for c++14\n";

    auto result = boost::apply_visitor([](auto&& v, auto&& t, auto&& p) { return lvalue_rvalue_detector()(FORWARD(v), FORWARD(t), FORWARD(p)); },
                test_var, test_var2, test_var3);
    std::cout << "result: " << result << std::endl;
    BOOST_TEST(result == "lvalue reference, lvalue reference, lvalue reference");
-#else
-    (void)test_var;
-    (void)test_var2;
-    (void)test_var3;
-#endif
 }

 void test_cpp14_visitor(variant_type& test_var)
@@ -248,18 +203,12 @@ void test_cpp14_visitor(variant_type& test_var, variant_type& test_var2)

 void test_cpp14_visitor(variant_type& test_var, variant_type& test_var2, variant_type& test_var3)
 {
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing lvalue visitable for c++14\n";

    auto result = boost::apply_visitor([](auto& v, auto& t, auto& p) { return lvalue_rvalue_detector()(v, t, p); },
                test_var, test_var2, test_var3);
    std::cout << "result: " << result << std::endl;
    BOOST_TEST(result == "lvalue reference, lvalue reference, lvalue reference");
-#else
-    (void)test_var;
-    (void)test_var2;
-    (void)test_var3;
-#endif
 }

 void test_cpp14_visitor(variant_type&& test_var)
@@ -279,21 +228,15 @@ void test_cpp14_visitor(variant_type&& test_var, variant_type&& test_var2)

 void test_cpp14_visitor(variant_type&& test_var, variant_type&& test_var2, variant_type&& test_var3)
 {
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing rvalue visitable for c++14\n";

    auto result = boost::apply_visitor([](auto&& v, auto&& t, auto&& p) { return lvalue_rvalue_detector()(FORWARD(v), FORWARD(t), FORWARD(p)); },
                std::move(test_var), std::move(test_var2), std::move(test_var3));
    std::cout << "result: " << result << std::endl;
    BOOST_TEST(result == "rvalue reference, rvalue reference, rvalue reference");
-#else
-    (void)test_var;
-    (void)test_var2;
-    (void)test_var3;
-#endif
 }

-#endif
+#endif  // #ifndef BOOST_NO_CXX14_DECLTYPE_AUTO

 void run_const_lvalue_ref_tests()
 {
@@ -305,53 +248,29 @@ void run_const_lvalue_ref_tests()

 void run_rvalue_ref_tests()
 {
-#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_NO_CXX11_REF_QUALIFIERS)
    variant_type v1(10), v2(20), v3(30);
-    test_rvalue_parameter(boost::move(v1));
-    test_rvalue_parameter2(boost::move(v2), boost::move(v3));
+    test_rvalue_parameter(std::move(v1));
+    test_rvalue_parameter2(std::move(v2), std::move(v3));

    variant_type vv1(100), vv2(200), vv3(300), vv4(400);
-    test_rvalue_parameter4(boost::move(vv1), boost::move(vv2), boost::move(vv3), boost::move(vv4));
-#endif
+    test_rvalue_parameter4(std::move(vv1), std::move(vv2), std::move(vv3), std::move(vv4));
 }

 void run_mixed_tests()
 {
    variant_type v1(1), v2(2);

-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
    std::cout << "Testing lvalue + rvalue visitable\n";
    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), v1, variant_type(10)) == "lvalue reference, rvalue reference");

    std::cout << "Testing rvalue + lvalue visitable\n";
    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), variant_type(10), v1) == "rvalue reference, lvalue reference");

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing rvalue + lvalue + rvalue visitable\n";
    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), variant_type(10), v1, variant_type(20)) == "rvalue reference, lvalue reference, rvalue reference");

    std::cout << "Testing lvalue + rvalue + lvalue + rvalue visitable\n";
    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), v1, variant_type(10), v2, variant_type(20)) == "lvalue reference, rvalue reference, lvalue reference, rvalue reference");
-#endif
-
-#endif // #ifndef BOOST_NO_CXX11_REF_QUALIFIERS
-
-#else // #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
-    std::cout << "Testing lvalue + rvalue visitable\n";
-    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), v1, v1) == "lvalue reference, lvalue reference");
-
-    std::cout << "Testing rvalue + lvalue visitable\n";
-    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), static_cast<const variant_type&>(variant_type(10)), v1) == "lvalue reference, lvalue reference");
-
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
-    std::cout << "Testing rvalue + lvalue + rvalue visitable\n";
-    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), static_cast<const variant_type&>(variant_type(10)), v1, static_cast<const variant_type&>(variant_type(20))) == "lvalue reference, lvalue reference, lvalue reference");
-
-    std::cout << "Testing lvalue + rvalue + lvalue + rvalue visitable\n";
-    BOOST_TEST(boost::apply_visitor(lvalue_rvalue_detector(), v1, static_cast<const variant_type&>(variant_type(10)), v2, static_cast<const variant_type&>(variant_type(20))) == "lvalue reference, lvalue reference, lvalue reference, lvalue reference");
-#endif
-#endif
 }

 void run_cpp14_mixed_tests()
@@ -367,7 +286,6 @@ void run_cpp14_mixed_tests()
    BOOST_TEST(boost::apply_visitor([](auto&& v, auto&& t) { return lvalue_rvalue_detector()(FORWARD(v), FORWARD(t)); },
                variant_type(10), v1) == "rvalue reference, lvalue reference");

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    std::cout << "Testing rvalue + lvalue + lvalue visitable\n";
    BOOST_TEST(boost::apply_visitor([](auto&& v, auto&& t, auto&& p) { return lvalue_rvalue_detector()(FORWARD(v), FORWARD(t), FORWARD(p)); },
                variant_type(10), v1, v2) == "rvalue reference, lvalue reference, lvalue reference");
@@ -375,8 +293,7 @@ void run_cpp14_mixed_tests()
    std::cout << "Testing lvalue + rvalue + lvalue visitable\n";
    BOOST_TEST(boost::apply_visitor([](auto&& v, auto&& t, auto&& p) { return lvalue_rvalue_detector()(FORWARD(v), FORWARD(t), FORWARD(p)); },
                v1, variant_type(10), v2) == "lvalue reference, rvalue reference, lvalue reference");
-#endif
-#endif
+#endif  // #ifndef BOOST_NO_CXX14_DECLTYPE_AUTO
 }

 void run_cpp14_tests()
@@ -395,11 +312,11 @@ void run_cpp14_tests()
    test_cpp14_visitor(v2, v3);
    test_cpp14_visitor(v1, v2, v3);

-    test_cpp14_visitor(boost::move(v1));
-    test_cpp14_visitor(boost::move(v2), boost::move(v3));
+    test_cpp14_visitor(std::move(v1));
+    test_cpp14_visitor(std::move(v2), std::move(v3));

    variant_type vv1(100), vv2(200), vv3(300);
-    test_cpp14_visitor(boost::move(vv1), boost::move(vv2), boost::move(vv3));
+    test_cpp14_visitor(std::move(vv1), std::move(vv2), std::move(vv3));
 #endif
 }

@@ -1,4 +1,4 @@
-// Copyright (c) 2021 Antony Polukhin
+// Copyright (c) 2021-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -8,8 +8,6 @@

 #include <boost/variant.hpp>

-#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
-
 #include <boost/fusion/include/vector.hpp>

 struct emptyList {};
@@ -29,5 +27,3 @@ IntList cons( int head, IntList tail )
 {
  return IntList( boost::fusion::vector<int, IntList>( head, tail ) );
 }
-
-#endif // #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011-2023 Antony Polukhin
+// Copyright (c) 2011-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2018-2023 Antony Polukhin
+// Copyright (c) 2018-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2019-2023 Antony Polukhin
+// Copyright (c) 2019-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -1,4 +1,4 @@
-// Copyright (c) 2017-2023 Antony Polukhin
+// Copyright (c) 2017-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman, Itay Maman
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -29,9 +29,7 @@
 #include <sstream>
 #include <vector>
 #include <map>
-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
 #include <tuple>
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)

 struct Nil {};

@@ -61,7 +59,6 @@ struct printer
        return ost.str();
    }

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    template <int...> struct indices {};
    template <typename... Ts, int... Is>
    std::string operator()(const std::tuple<Ts...>& tup, indices<Is...>) const
@@ -83,7 +80,6 @@ struct printer
    {
        return printer()(tup, make_indices<sizeof...(Ts)>());
    }
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)

    template <typename T>
    std::string operator()(const T& operand) const
@@ -215,7 +211,6 @@ void test_recursive_variant()
        >::type var6_t;
    var6_t var6;

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
    typedef boost::make_recursive_variant<
          int,
          std::tuple<int, boost::recursive_variant_>
@@ -228,7 +223,6 @@ void test_recursive_variant()

    std::cout << "result7: " << result7 << '\n';
    BOOST_TEST(result7 == "( 2 ( 1 0 ) ) ");
-#endif // !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX11_HDR_TUPLE)
 }

 void test_recursive_variant_over()
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2012-2023 Antony Polukhin
+// Copyright (c) 2012-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -17,7 +17,6 @@
 #include "boost/mpl/bool.hpp"

 #include <boost/blank.hpp>
-#include <boost/swap.hpp>

 namespace swap_ambiguouty_test_ns {
    struct A {};
@@ -39,11 +38,11 @@ public:
    static unsigned int copy_count;

    move_copy_conting_class(){}
-    move_copy_conting_class(BOOST_RV_REF(move_copy_conting_class) ) {
+    move_copy_conting_class(move_copy_conting_class&& ) {
        ++ moves_count;
    }

-    move_copy_conting_class& operator=(BOOST_RV_REF(move_copy_conting_class) ) {
+    move_copy_conting_class& operator=(move_copy_conting_class&& ) {
        ++ moves_count;
        return *this;
    }
@@ -51,7 +50,7 @@ public:
    move_copy_conting_class(const move_copy_conting_class&) {
        ++ copy_count;
    }
-    move_copy_conting_class& operator=(BOOST_COPY_ASSIGN_REF(move_copy_conting_class) ) {
+    move_copy_conting_class& operator=(const move_copy_conting_class& ) {
        ++ copy_count;
        return *this;
    }
@@ -60,53 +59,6 @@ public:
 unsigned int move_copy_conting_class::moves_count = 0;
 unsigned int move_copy_conting_class::copy_count = 0;

-#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
-
-void run()
-{
-    // Making sure that internals of Boost.Move do not interfere with
-    // internals of Boost.Variant and in case of C++03 or C++98 compilation 
-    // is still possible.
-    typedef boost::variant<int, move_copy_conting_class> variant_I_type;
-    variant_I_type v1, v2;
-    v1 = move_copy_conting_class();
-    v2 = v1; 
-    v2 = boost::move(v1);
-    v1.swap(v2);
-
-    move_copy_conting_class val;
-    v2 = boost::move(val);
-    v2 = 10;
-
-    variant_I_type v3(boost::move(val));
-    variant_I_type v4(boost::move(v1));
-}
-
-void run1()
-{
-    BOOST_TEST(true);
-}
-
-void run_move_only()
-{
-    BOOST_TEST(true);
-}
-
-void run_moves_are_noexcept()
-{
-    BOOST_TEST(true);
-}
-
-
-void run_const_rvalues()
-{
-    BOOST_TEST(true);
-}
-
-
-#else 
-
-
 void run()
 {
    typedef boost::variant<int, move_copy_conting_class> variant_I_type;
@@ -131,7 +83,7 @@ void run()

    move_copy_conting_class::moves_count = 0;
    move_copy_conting_class::copy_count = 0;
-    v2 = boost::move(v1);
+    v2 = std::move(v1);
    // Assuring that `move_copy_conting_class` in v1 was moved at least once and was not copied
    BOOST_TEST(move_copy_conting_class::moves_count != 0);
    BOOST_TEST(move_copy_conting_class::copy_count == 0);
@@ -139,7 +91,7 @@ void run()
    v1 = move_copy_conting_class();
    move_copy_conting_class::moves_count = 0;
    move_copy_conting_class::copy_count = 0;
-    v2 = boost::move(v1);
+    v2 = std::move(v1);
    // Assuring that `move_copy_conting_class` in v1 was moved at least once and was not copied
    BOOST_TEST(move_copy_conting_class::moves_count != 0);
    BOOST_TEST(move_copy_conting_class::copy_count == 0);
@@ -155,19 +107,19 @@ void run()
    variant_II_type v3;
    move_copy_conting_class::moves_count = 0;
    move_copy_conting_class::copy_count = 0;
-    v1 = boost::move(v3);
+    v1 = std::move(v3);
    // Assuring that `move_copy_conting_class` in v3 was moved at least once (v1 and v3 have different types)
    BOOST_TEST(move_copy_conting_class::moves_count != 0);

    move_copy_conting_class::moves_count = 0;
    move_copy_conting_class::copy_count = 0;
-    v2 = boost::move(v1);
+    v2 = std::move(v1);
    // Assuring that `move_copy_conting_class` in v1 was moved at least once (v1 and v3 have different types)
    BOOST_TEST(move_copy_conting_class::moves_count != 0);

    move_copy_conting_class::moves_count = 0;
    move_copy_conting_class::copy_count = 0;
-    variant_I_type v5(boost::move(v1));
+    variant_I_type v5(std::move(v1));
    // Assuring that `move_copy_conting_class` in v1 was moved at least once and was not copied
    BOOST_TEST(move_copy_conting_class::moves_count != 0);
    BOOST_TEST(move_copy_conting_class::copy_count == 0);
@@ -187,7 +139,7 @@ void run1()

    move_copy_conting_class c1;
    typedef boost::variant<int, move_copy_conting_class> variant_I_type;
-    variant_I_type v1(boost::move(c1));
+    variant_I_type v1(std::move(c1));
    
    // Assuring that `move_copy_conting_class` was not copyied
    BOOST_TEST(move_copy_conting_class::copy_count == 0);
@@ -267,19 +219,16 @@ void run_const_rvalues()
    v4 = get_string();
    v5 = get_variant();
    v6 = get_variant2();
-    v7 = boost::move(v1);
+    v7 = std::move(v1);
 }

-#endif
-
 struct nothrow_copyable_throw_movable {
    nothrow_copyable_throw_movable(){}
    nothrow_copyable_throw_movable(const nothrow_copyable_throw_movable&) BOOST_NOEXCEPT {}
    nothrow_copyable_throw_movable& operator=(const nothrow_copyable_throw_movable&) BOOST_NOEXCEPT { return *this; }
-#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+
    nothrow_copyable_throw_movable(nothrow_copyable_throw_movable&&) BOOST_NOEXCEPT_IF(false) {}
    nothrow_copyable_throw_movable& operator=(nothrow_copyable_throw_movable&&) BOOST_NOEXCEPT_IF(false) { return *this; }
-#endif
 };

 // This test is created to cover the following situation:
@@ -320,13 +269,5 @@ int main()
   run_const_rvalues();
   run_is_container_compilation_test();

-#if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && defined(__GNUC__) && (__GNUC__ == 4) && (__GNUC_MINOR__ > 6)
-#   ifdef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
-        BOOST_TEST(false && 
-            "Something wrong with macro definitions. GCC-4.7+ is known to work with variadic templates"
-        );
-#   endif
-#endif
-
   return boost::report_errors();
 }
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2016-2023 Antony Polukhin
+// Copyright (c) 2016-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman, Itay Maman
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -386,7 +386,7 @@ inline void get_rvref_test()
  boost::variant<MoveonlyType, int> v;

  v = MoveonlyType();
-  boost::get<MoveonlyType>(boost::move(v));
+  boost::get<MoveonlyType>(std::move(v));

  v = 3;

@@ -396,7 +396,7 @@ inline void get_rvref_test()
  boost::relaxed_get<MoveonlyType&>(boost::variant<MoveonlyType, int>());

  v = MoveonlyType();
-  MoveonlyType moved_from_variant(boost::get<MoveonlyType>(boost::move(v)));
+  MoveonlyType moved_from_variant(boost::get<MoveonlyType>(std::move(v)));
 }
 #endif  // BOOST_NO_CXX11_RVALUE_REFERENCES

@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -135,14 +135,12 @@ int main()
        arithmetics_t(true)
    );

-#if !defined(BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES)
    if_visitor if_vis;
    BOOST_TEST(
        boost::apply_visitor(if_vis)(v0, v1, v2)
        ==
        arithmetics_t(true)
    );
-#endif


    variant_noncopy_t vnonc[6];
@@ -3,7 +3,7 @@
 // See http://www.boost.org for updates, documentation, and revision history.
 //-----------------------------------------------------------------------------
 //
-// Copyright (c) 2014-2023 Antony Polukhin
+// Copyright (c) 2014-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2003 Eric Friedman
-// Copyright (c) 2013-2023 Antony Polukhin
+// Copyright (c) 2013-2026 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -13,7 +13,6 @@
 #include "boost/variant/variant.hpp"
 #include "boost/core/lightweight_test.hpp"

-#include <boost/move/move.hpp>
 #include <boost/static_assert.hpp>

 #include <string>
@@ -29,7 +28,7 @@ inline void run()
    var_t v = s;

    // must spit an error at compile-time because of 'std::string&'
-    std::string new_s = boost::strict_get<std::string&>(boost::move(v));
+    std::string new_s = boost::strict_get<std::string&>(std::move(v));
    UNUSED(new_s);
 #else
    BOOST_STATIC_ASSERT_MSG(false, "Dummy compile-time error to pass the test on C++03");
@@ -4,7 +4,7 @@
 //-----------------------------------------------------------------------------
 //
 // Copyright (c) 2009 ArtVPS Ltd.
-// Copyright (c) 2013-2023 Antony Polukhin.
+// Copyright (c) 2013-2026 Antony Polukhin.
 //
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
@@ -79,7 +79,7 @@ struct rvalue_ref_decltype_visitor
 #endif

 template <typename Checker, typename Variant>
-inline void unary_test(Variant& var, Checker* = BOOST_VARIANT_NULL)
+inline void unary_test(Variant& var, Checker* = nullptr)
 {
    Checker checker;
    const Checker& const_checker = checker;
@@ -97,7 +97,7 @@ inline void unary_test(Variant& var, Checker* = BOOST_VARIANT_NULL)
 }

 template <typename Checker, typename Variant1, typename Variant2>
-inline void binary_test(Variant1& var1, Variant2& var2, Checker* = BOOST_VARIANT_NULL)
+inline void binary_test(Variant1& var1, Variant2& var2, Checker* = nullptr)
 {
    Checker checker;
    const Checker& const_checker = checker;
Author	SHA1	Message	Date
Peter Dimov	e8cb128f99	Merge pull request #115 from Lastique/feature/remove_static_assert Remove dependencies on Boost.StaticAssert	2026-04-25 20:51:34 +03:00
Andrey Semashev	5e1fe395b6	Remove dependencies on Boost.StaticAssert. Boost.StaticAssert has been merged into Boost.Config, so remove the dependency.	2026-01-22 22:52:11 +03:00
Antony Polukhin	fdf2c0f646	Update copyright years	2026-01-04 11:27:21 +03:00
dependabot[bot]	0d822a9b73	Bump actions/checkout from 2 to 6 (#114 ) Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 6. - [Release notes](https://github.com/actions/checkout/releases) - [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md) - [Commits](https://github.com/actions/checkout/compare/v2...v6) --- updated-dependencies: - dependency-name: actions/checkout dependency-version: '6' dependency-type: direct:production update-type: version-update:semver-major ... Signed-off-by: dependabot[bot] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>	2025-12-29 12:31:14 +03:00
Antony Polukhin	cf72f05cef	Add dependabot	2025-12-24 20:23:02 +03:00
Antony Polukhin	9738f5733b	CI fixes (#113 )	2025-09-13 13:52:35 +03:00
Alexander Grund	a803f3f1dd	Update Link to regression test matrix in README (#112 )	2025-08-26 13:00:54 +03:00
Antony Polukhin	1fd7271d2e	Update copyright years	2025-01-08 19:52:10 +03:00
Antony Polukhin	36fc992f51	Do not test on MinGW 32-bit any more	2024-12-19 18:56:14 +03:00
René Ferdinand Rivera Morell	0fd179fbd8	Add support for modular build structure. (#111 ) This is part of the effort to make the Boost libraries "modular" for build and consumption. See https://lists.boost.org/Archives/boost/2024/01/255704.php and https://github.com/grafikrobot/boost-b2-modular/blob/b2-modular/README.adoc for more information. This PR depends on the following other PRs being merged to both develop and master branches of the respective repos: - https://github.com/boostorg/boost/pull/854	2024-08-24 12:40:30 +03:00
Antony Polukhin	b33ff4f811	Remove obsolete code (#109 )	2024-01-08 20:13:32 +03:00
Antony Polukhin	e37df948d7	Update copyright years	2024-01-07 12:56:27 +03:00
Andrey Semashev	9d1e62f33c	Remove deprecated boost/swap.hpp include. (#108 ) This header is deprecated and will be removed. There is boost/core/invoke_swap.hpp as a replacement, but it isn't needed in this case.	2023-09-03 11:23:14 +03:00
Antony Polukhin	7b45064ed8	Drop C++03 support (#107 ) Drop boost::move and boost::bind dependencies. Use Boost.PP in less cases	2023-08-25 16:02:34 +03:00
Antony Polukhin	d48711fb84	update CI	2023-05-22 09:18:54 +03:00
Antony Polukhin	a3368f0cf8	add C++03 deprecation warnings	2023-05-14 20:10:13 +03:00