has_xxx checkin

[SVN r16160]

include/boost/mpl/aux_/has_xxx.hpp

@@ -0,0 +1,126 @@
+//-----------------------------------------------------------------------------
+// boost mpl/aux_/has_xxx.hpp header file
+// See http://www.boost.org for updates, documentation, and revision history.
+//-----------------------------------------------------------------------------
+//
+// Copyright (c) 2002
+// Aleksey Gurtovoy
+//
+// Permission to use, copy, modify, distribute and sell this software
+// and its documentation for any purpose is hereby granted without fee, 
+// provided that the above copyright notice appears in all copies and 
+// that both the copyright notice and this permission notice appear in 
+// supporting documentation. No representations are made about the 
+// suitability of this software for any purpose. It is provided "as is" 
+// without express or implied warranty.
+
+#ifndef BOOST_MPL_AUX_HAS_XXX_HPP_INCLUDED
+#define BOOST_MPL_AUX_HAS_XXX_HPP_INCLUDED
+
+#include "boost/mpl/aux_/type_wrapper.hpp"
+#include "boost/mpl/aux_/yes_no.hpp"
+#include "boost/mpl/aux_/config/msvc_typename.hpp"
+#include "boost/mpl/aux_/config/overload_resolution.hpp"
+#include "boost/config.hpp"
+
+#if !defined(BOOST_MPL_BROKEN_OVERLOAD_RESOLUTION)
+
+#   if !defined(BOOST_MSVC) || BOOST_MSVC > 1300
+
+// the implementation below is based on a USENET newsgroup's posting by  
+// Rani Sharoni (comp.lang.c++.moderated, 2002-03-17 07:45:09 PST)
+
+#   define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
+template< typename T > \
+boost::mpl::aux::yes_tag \
+has_##name##_helper( \
+      boost::mpl::aux::type_wrapper<T>* \
+    , BOOST_MSVC_TYPENAME T::name* \
+    ); \
+\
+template< typename T > \
+no_tag has_##name##_helper( \
+      boost::mpl::aux::type_wrapper<T>* \
+    , ... \
+    ); \
+\
+template< typename T > \
+struct has_##name \
+{ \
+     BOOST_STATIC_CONSTANT(bool, value =  \
+        sizeof(has_##name##_helper((boost::mpl::aux::type_wrapper<T>*)0, 0)) \
+            == sizeof(boost::mpl::aux::yes_tag) \
+        ); \
+}; \
+/**/
+
+#   else
+
+// agurt, 11/sep/02: MSVC version, based on a USENET newsgroup's posting by 
+// John Madsen (comp.lang.c++.moderated, 1999-11-12 19:17:06 GMT);
+// note that the code is _not_ standard-conforming, but it works, 
+// and it resolves some nasty ICE cases with the above implementation
+
+#   define BOOST_MPL_HAS_XXX_TRAIT_DEF_(name) \
+template< typename T, typename name = int > \
+struct has_##name : T \
+{ \
+ private: \
+    static boost::mpl::aux::no_tag test(int*); \
+    static boost::mpl::aux::yes_tag test(...); \
+\
+ public: \
+    BOOST_STATIC_CONSTANT(bool, value =  \
+        sizeof(test(static_cast<name*>(0))) != sizeof(boost::mpl::aux::no_tag) \
+        ); \
+}; \
+\
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, void) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, bool) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, char) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, signed char) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, unsigned char) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, signed short) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, unsigned short) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, signed int) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, unsigned int) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, signed long) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, unsigned long) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, float) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, double) \
+BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, long double) \
+/**/
+
+#   define BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, T) \
+template<> struct has_##name<T,int> \
+{ \
+    enum { value = false }; \
+}; \
+/**/
+
+#if !defined(BOOST_NO_INTRINSIC_WCHAR_T)
+#   define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
+    BOOST_MPL_HAS_XXX_TRAIT_DEF_(name) \
+    BOOST_MPL_AUX_HAS_XXX_TRAIT_SPEC(name, wchar_t) \
+    /**/
+#else
+#   define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
+    BOOST_MPL_HAS_XXX_TRAIT_DEF_(name) \
+    /**/
+#endif
+
+#   endif // BOOST_MSVC > 1300
+
+#else 
+
+#   define BOOST_MPL_HAS_XXX_TRAIT_DEF(name) \
+template< typename T > \
+struct has_##name \
+{ \
+     BOOST_STATIC_CONSTANT(bool, value = false); \
+}; \
+/**/
+
+#endif // BOOST_MPL_BROKEN_OVERLOAD_RESOLUTION
+
+#endif // BOOST_MPL_AUX_HAS_XXX_HPP_INCLUDED