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

Author: grafikrobot

build.jam

@@ -5,26 +5,29 @@
 
 require-b2 5.2 ;
 
+constant boost_dependencies :
+    /boost/array//boost_array
+    /boost/config//boost_config
+    /boost/core//boost_core
+    /boost/move//boost_move
+    /boost/preprocessor//boost_preprocessor
+    /boost/ptr_container//boost_ptr_container
+    /boost/range//boost_range
+    /boost/static_assert//boost_static_assert
+    /boost/throw_exception//boost_throw_exception
+    /boost/tuple//boost_tuple
+    /boost/type_traits//boost_type_traits ;
+
 project /boost/assign
     : common-requirements
-        <library>/boost/array//boost_array
-        <library>/boost/config//boost_config
-        <library>/boost/core//boost_core
-        <library>/boost/move//boost_move
-        <library>/boost/preprocessor//boost_preprocessor
-        <library>/boost/ptr_container//boost_ptr_container
-        <library>/boost/range//boost_range
-        <library>/boost/static_assert//boost_static_assert
-        <library>/boost/throw_exception//boost_throw_exception
-        <library>/boost/tuple//boost_tuple
-        <library>/boost/type_traits//boost_type_traits
         <include>include
     ;
 
 explicit
-    [ alias boost_assign ]
+    [ alias boost_assign : : : : <library>$(boost_dependencies) ]
     [ alias all : boost_assign test ]
     ;
 
 call-if : boost-library assign
     ;
+