templatetools.hpp

00001 /*
00002 Copyright © 2010  yan Verdavaine
00003 
00004 This file is part of QExtend.
00005 
00006 QExtend is free software: you can redistribute it and/or modify
00007 it under the terms of the GNU General Public License as published by
00008 the Free Software Foundation, either version 3 of the License, or
00009 any later version.
00010 
00011 QExtend is distributed in the hope that it will be useful,
00012 but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 GNU General Public License for more details.
00015 
00016 You should have received a copy of the GNU General Public License
00017 along with QExtend.  If not, see <http://www.gnu.org/licenses/>.
00018 */
00019 
00020 #ifndef QEXTEND_TEMPLATETOOLS_H
00021 #define QEXTEND_TEMPLATETOOLS_H
00022 namespace QExtend
00023 {
00024 
00025 
00026 
00027 
00028 
00029 
00030 template<typename D, typename B>
00031 class IsDerivedFrom
00032 {
00033 //internal dev not cocumented
00034   class No { };
00035   class Yes { No no[3]; }; 
00036 
00037   static Yes Test( B* ); // declared, but not defined
00038   static No Test( ... ); // declared, but not defined 
00039 
00040 public:
00041   //
00042   static const bool val = sizeof(Test(static_cast<D*>(0))) == sizeof(Yes);
00043 };
00044 
00045 template<typename T, typename Sig>                                 
00046 class has_hello {    
00047     class No { };
00048     class Yes { No no[3]; }; 
00049 
00050     template <typename U, Sig> struct type_check;
00051 
00052     template <typename V> static Yes Test(type_check<V, &V::hello>*);
00053     template <typename  > static No Test (...); 
00054 public :  
00055     static const bool val = sizeof(Test<T>(0)) == sizeof(Yes);
00056 
00057 };
00058 
00059 
00060 template<typename T, typename Sig>                                 
00061 class has_hello2 {    
00062     class No { };
00063     class Yes { No no[3]; }; 
00064 
00065     template <typename U, U> struct type_check;
00066 
00067     template <typename V> static Yes Test(type_check<Sig V::*, &V::hello>*);
00068     template <typename V> static Yes Test(type_check<Sig, &V::hello>*);
00069     template <typename  > static No Test (...); 
00070 public :  
00071     static const bool val = sizeof(Test<T>(0)) == sizeof(Yes);
00072 
00073 };
00074 
00075 
00076 
00077 
00078 
00079 }
00080 #endif