1 ///////////////////////////////////////////////////////////////////////////// 2 // Name: wx/meta/pod.h 3 // Purpose: Test if a type is POD 4 // Author: Vaclav Slavik, Jaakko Salli 5 // Created: 2010-06-14 6 // Copyright: (c) wxWidgets team 7 // Licence: wxWindows licence 8 ///////////////////////////////////////////////////////////////////////////// 9 10 #ifndef _WX_META_POD_H_ 11 #define _WX_META_POD_H_ 12 13 #include "wx/defs.h" 14 15 // 16 // TODO: Use TR1 is_pod<> implementation where available. VC9 SP1 has it 17 // in tr1 namespace, VC10 has it in std namespace. GCC 4.2 has it in 18 // <tr1/type_traits>, while GCC 4.3 and later have it in <type_traits>. 19 // 20 21 // This macro declares something called "value" inside a class declaration. 22 // 23 // It has to be used because VC6 doesn't handle initialization of the static 24 // variables in the class declaration itself while BCC5.82 doesn't understand 25 // enums (it compiles the template fine but can't use it later) 26 #if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7) 27 #define wxDEFINE_TEMPLATE_BOOL_VALUE(val) enum { value = val } 28 #else 29 #define wxDEFINE_TEMPLATE_BOOL_VALUE(val) static const bool value = val 30 #endif 31 32 // Helper to decide if an object of type T is POD (Plain Old Data) 33 template<typename T> 34 struct wxIsPod 35 { 36 wxDEFINE_TEMPLATE_BOOL_VALUE(false); 37 }; 38 39 // Macro to add wxIsPod<T> specialization for given type that marks it 40 // as Plain Old Data: 41 #define WX_DECLARE_TYPE_POD(type) \ 42 template<> struct wxIsPod<type> \ 43 { \ 44 wxDEFINE_TEMPLATE_BOOL_VALUE(true); \ 45 }; 46 47 WX_DECLARE_TYPE_POD(bool) 48 WX_DECLARE_TYPE_POD(unsigned char) 49 WX_DECLARE_TYPE_POD(signed char) 50 WX_DECLARE_TYPE_POD(unsigned int) 51 WX_DECLARE_TYPE_POD(signed int) 52 WX_DECLARE_TYPE_POD(unsigned short int) 53 WX_DECLARE_TYPE_POD(signed short int) 54 WX_DECLARE_TYPE_POD(signed long int) 55 WX_DECLARE_TYPE_POD(unsigned long int) 56 WX_DECLARE_TYPE_POD(float) 57 WX_DECLARE_TYPE_POD(double) 58 WX_DECLARE_TYPE_POD(long double) 59 #if wxWCHAR_T_IS_REAL_TYPE 60 WX_DECLARE_TYPE_POD(wchar_t) 61 #endif 62 #ifdef wxLongLong_t 63 WX_DECLARE_TYPE_POD(wxLongLong_t) 64 WX_DECLARE_TYPE_POD(wxULongLong_t) 65 #endif 66 67 // Visual C++ 6.0 can't compile partial template specializations and as this is 68 // only an optimization, we can live with pointers not being recognized as 69 // POD types under VC6 70 #if !defined(__VISUALC__) || wxCHECK_VISUALC_VERSION(7) 71 72 // pointers are Plain Old Data: 73 template<typename T> 74 struct wxIsPod<T*> 75 { 76 static const bool value = true; 77 }; 78 79 template<typename T> 80 struct wxIsPod<const T*> 81 { 82 static const bool value = true; 83 }; 84 85 #endif // !VC++ < 7 86 87 #endif // _WX_META_POD_H_ 88