Milena (Olena)
User documentation 2.0a Id
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00001 // Copyright (C) 2007, 2008, 2009 EPITA Research and Development Laboratory (LRDE) 00002 // 00003 // This file is part of Olena. 00004 // 00005 // Olena is free software: you can redistribute it and/or modify it under 00006 // the terms of the GNU General Public License as published by the Free 00007 // Software Foundation, version 2 of the License. 00008 // 00009 // Olena is distributed in the hope that it will be useful, 00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00012 // General Public License for more details. 00013 // 00014 // You should have received a copy of the GNU General Public License 00015 // along with Olena. If not, see <http://www.gnu.org/licenses/>. 00016 // 00017 // As a special exception, you may use this file as part of a free 00018 // software project without restriction. Specifically, if other files 00019 // instantiate templates or use macros or inline functions from this 00020 // file, or you compile this file and link it with other files to produce 00021 // an executable, this file does not by itself cause the resulting 00022 // executable to be covered by the GNU General Public License. This 00023 // exception does not however invalidate any other reasons why the 00024 // executable file might be covered by the GNU General Public License. 00025 00026 #ifndef MLN_METAL_IS_A_HH 00027 # define MLN_METAL_IS_A_HH 00028 00032 00033 # include <mln/metal/bool.hh> 00034 00035 00044 # define mlc_is_a(T, M) mln::metal::is_a<T, M> 00045 00046 00047 // Allows to write somthing like "mlc_is_a(T<P1,P2>, M)" without 00048 // getting trouble with the preprocessor due to the 1st comma. 00049 # define mlc_is_a__1comma(Tleft, Tright, M) mln::metal::is_a< Tleft,Tright , M > 00050 00051 00052 00053 namespace mln 00054 { 00055 00056 namespace metal 00057 { 00058 00059 namespace internal 00060 { 00061 00062 typedef char yes_; 00063 struct no_ { char dummy[2]; }; 00064 00065 template <typename T> 00066 struct make_ 00067 { 00068 static T* ptr(); 00069 }; 00070 00071 template <typename T> 00072 struct make_< T& > 00073 { 00074 static T* ptr(); 00075 }; 00076 00077 template <typename T, template <class> class M> 00078 struct helper_is_a_ 00079 { 00080 00081 template<class V> 00082 static yes_ selector(M<V>*); 00083 static no_ selector(...); 00084 }; 00085 00086 } // end of namespace mln::metal::internal 00087 00088 00089 00093 // 00094 template <typename T, template <class> class M> 00095 struct is_a : bool_<( sizeof( internal::helper_is_a_< T, M >::selector(internal::make_< T >::ptr()) ) 00096 == 00097 sizeof( internal::yes_ ) )> 00098 {}; 00099 00100 template <typename T, template <class> class M> 00101 struct is_a< const T, M > : is_a< T, M >::eval 00102 {}; 00103 00104 template <typename T, template <class> class M> 00105 struct is_a< T&, M > : is_a< T, M >::eval 00106 {}; 00107 00108 template <typename T, template <class> class M> 00109 struct is_a< const T&, M > : is_a< T, M >::eval 00110 {}; 00111 00112 00113 } // end of namespace mln::metal 00114 00115 } // end of namespace mln 00116 00117 00118 #endif // ! MLN_METAL_IS_A_HH