Avoid allocation on interop for system/generic categories; fix DLL interoperability on msvc-14.x by poking into std::system_category::_Addr

include/boost/system/detail/std_interoperability.hpp

@@ -30,8 +30,20 @@ private:
 
 public:
 
-    explicit std_category( boost::system::error_category const * pc ): pc_( pc )
+    explicit std_category( boost::system::error_category const * pc, unsigned id ): pc_( pc )
     {
+        if( id != 0 )
+        {
+#if defined(_MSC_VER) && defined(_CPPLIB_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000
+
+            // Poking into the protected _Addr member of std::error_category
+            // is not a particularly good programming practice, but what can
+            // you do
+
+            _Addr = id;
+
+#endif
+        }
     }
 
     virtual const char * name() const BOOST_NOEXCEPT
@@ -55,24 +67,45 @@ public:
 
 inline std::error_category const & to_std_category( boost::system::error_category const & cat ) BOOST_SYMBOL_VISIBLE;
 
+struct cat_ptr_less
+{
+    bool operator()( boost::system::error_category const * p1, boost::system::error_category const * p2 ) const BOOST_NOEXCEPT
+    {
+        return *p1 < *p2;
+    }
+};
+
 inline std::error_category const & to_std_category( boost::system::error_category const & cat )
 {
-    typedef std::map< boost::system::error_category const *, std::unique_ptr<std_category> > map_type;
-
-    static map_type map_;
-
-    map_type::iterator i = map_.find( &cat );
-
-    if( i == map_.end() )
+    if( cat == boost::system::system_category() )
     {
-        std::unique_ptr<std_category> p( new std_category( &cat ) );
-
-        std::pair<map_type::iterator, bool> r = map_.insert( map_type::value_type( &cat, std::move( p ) ) );
-
-        i = r.first;
+        static const std_category system_instance( &cat, 0x1F4D7 );
+        return system_instance;
     }
+    else if( cat == boost::system::generic_category() )
+    {
+        static const std_category generic_instance( &cat, 0x1F4D3 );
+        return generic_instance;
+    }
+    else
+    {
+        typedef std::map< boost::system::error_category const *, std::unique_ptr<std_category>, cat_ptr_less > map_type;
 
-    return *i->second;
+        static map_type map_;
+
+        map_type::iterator i = map_.find( &cat );
+
+        if( i == map_.end() )
+        {
+            std::unique_ptr<std_category> p( new std_category( &cat, 0 ) );
+
+            std::pair<map_type::iterator, bool> r = map_.insert( map_type::value_type( &cat, std::move( p ) ) );
+
+            i = r.first;
+        }
+
+        return *i->second;
+    }
 }
 
 inline bool std_category::equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT

test/Jamfile.v2

@@ -68,4 +68,4 @@ lib std_single_instance_lib2 : std_single_instance_2.cpp : <link>shared:<define>
 
 system-run std_single_instance_test.cpp std_single_instance_1.cpp std_single_instance_2.cpp ;
 run std_single_instance_test.cpp std_single_instance_lib1 std_single_instance_lib2 : : : <link>static : std_single_instance_lib_static ;
-run std_single_instance_test.cpp std_single_instance_lib1 std_single_instance_lib2 : : : <link>shared : std_single_instance_lib_shared ;
+run std_single_instance_test.cpp std_single_instance_lib1 std_single_instance_lib2 : : : <link>shared <define>STD_SINGLE_INSTANCE_SHARED : std_single_instance_lib_shared ;

test/std_single_instance_1.cpp

@@ -31,4 +31,10 @@ EXPORT std::error_code get_generic_code()
 
 } // namespace lib1
 
+#else
+
+EXPORT void lib1_f()
+{
+}
+
 #endif

test/std_single_instance_2.cpp

@@ -31,4 +31,10 @@ EXPORT std::error_code get_generic_code()
 
 } // namespace lib2
 
+#else
+
+EXPORT void lib2_f()
+{
+}
+
 #endif

test/std_single_instance_test.cpp

@@ -4,11 +4,31 @@
 
 #include <boost/system/error_code.hpp>
 #include <boost/config/pragma_message.hpp>
+#include <boost/config/helper_macros.hpp>
 
 #if !defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
 
 BOOST_PRAGMA_MESSAGE( "BOOST_SYSTEM_HAS_SYSTEM_ERROR not defined, test will be skipped" )
+int main() {}
 
+#elif defined(STD_SINGLE_INSTANCE_SHARED) && defined(__CYGWIN__)
+
+BOOST_PRAGMA_MESSAGE( "Skipping Windows/DLL test, __CYGWIN__" )
+int main() {}
+
+#elif defined(STD_SINGLE_INSTANCE_SHARED) && defined(_WIN32) && !defined(_MSC_VER)
+
+BOOST_PRAGMA_MESSAGE( "Skipping Windows/DLL test, no _MSC_VER" )
+int main() {}
+
+#elif defined(STD_SINGLE_INSTANCE_SHARED) && defined(_WIN32) && !defined(_CPPLIB_VER)
+
+BOOST_PRAGMA_MESSAGE( "Skipping Windows/DLL test, no _CPPLIB_VER" )
+int main() {}
+
+#elif defined(STD_SINGLE_INSTANCE_SHARED) && defined(_WIN32) && (_MSC_VER < 1900 || _MSC_VER >= 2000)
+
+BOOST_PRAGMA_MESSAGE( "Skipping Windows/DLL test, _MSC_VER is " BOOST_STRINGIZE(_MSC_VER) )
 int main() {}
 
 #else