Move inter-lib dependencies to a project variable and into the build targets.

build.jam

@@ -5,18 +5,20 @@
 
 require-b2 5.2 ;
 
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/context//boost_context
+    /boost/core//boost_core
+    /boost/exception//boost_exception
+    /boost/move//boost_move
+    /boost/system//boost_system
+    /boost/throw_exception//boost_throw_exception
+    /boost/type_traits//boost_type_traits
+    /boost/utility//boost_utility ;
+
 project /boost/coroutine
     : common-requirements
-        <library>/boost/assert//boost_assert
-        <library>/boost/config//boost_config
-        <library>/boost/context//boost_context
-        <library>/boost/core//boost_core
-        <library>/boost/exception//boost_exception
-        <library>/boost/move//boost_move
-        <library>/boost/system//boost_system
-        <library>/boost/throw_exception//boost_throw_exception
-        <library>/boost/type_traits//boost_type_traits
-        <library>/boost/utility//boost_utility
         <include>include
     ;
 
@@ -28,3 +30,4 @@ explicit
 call-if : boost-library coroutine
     : install boost_coroutine
     ;
+

build/Jamfile.v2

@@ -9,6 +9,7 @@ import modules ;
 import toolset ;
 
 project
+    : common-requirements <library>$(boost_dependencies)
     : requirements
       <library>/boost/context//boost_context
       <target-os>linux,<toolset>gcc,<segmented-stacks>on:<cxxflags>-fsplit-stack