|
CppCMS
|
00001 #ifndef BOOSTER_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED 00002 #define BOOSTER_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED 00003 00004 00005 // detail/sp_convertible.hpp 00006 // 00007 // Copyright 2008 Peter Dimov 00008 // 00009 // Distributed under the Boost Software License, Version 1.0. 00010 // See accompanying file LICENSE_1_0.txt or copy at 00011 // http://www.boost.org/LICENSE_1_0.txt 00012 00013 #include <booster/config.h> 00014 00015 namespace booster 00016 { 00017 00018 namespace detail 00019 { 00020 00021 template< class Y, class T > struct sp_convertible 00022 { 00023 typedef char (&yes) [1]; 00024 typedef char (&no) [2]; 00025 00026 static yes f( T* ); 00027 static no f( ... ); 00028 00029 enum _vt { value = sizeof( f( static_cast<Y*>(0) ) ) == sizeof(yes) }; 00030 }; 00031 00032 struct sp_empty 00033 { 00034 }; 00035 00036 template< bool > struct sp_enable_if_convertible_impl; 00037 00038 template<> struct sp_enable_if_convertible_impl<true> 00039 { 00040 typedef sp_empty type; 00041 }; 00042 00043 template<> struct sp_enable_if_convertible_impl<false> 00044 { 00045 }; 00046 00047 template< class Y, class T > struct sp_enable_if_convertible: public sp_enable_if_convertible_impl< sp_convertible< Y, T >::value > 00048 { 00049 }; 00050 00051 } // namespace detail 00052 00053 } // namespace boost 00054 00055 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_CONVERTIBLE_HPP_INCLUDED
1.7.6.1