Added wxIsPod<>. Use it in wxAny instead of wxIsMovable<>.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64589 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/meta/pod.h

@@ -0,0 +1,88 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        wx/meta/pod.h
+// Purpose:     Test if a type is POD
+// Author:      Vaclav Slavik, Jaakko Salli
+// Created:     2010-06-14
+// RCS-ID:      $Id$
+// Copyright:   (c) wxWidgets team
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_META_POD_H_
+#define _WX_META_POD_H_
+
+#include "wx/defs.h"
+
+//
+// TODO: Use TR1 is_pod<> implementation where available. VC9 SP1 has it
+//       in tr1 namespace, VC10 has it in std namespace. GCC 4.2 has it in
+//       <tr1/type_traits>, while GCC 4.3 and later have it in <type_traits>.
+//
+
+// This macro declares something called "value" inside a class declaration.
+//
+// It has to be used because VC6 doesn't handle initialization of the static
+// variables in the class declaration itself while BCC5.82 doesn't understand
+// enums (it compiles the template fine but can't use it later)
+#if defined(__VISUALC__) && !wxCHECK_VISUALC_VERSION(7)
+    #define wxDEFINE_TEMPLATE_BOOL_VALUE(val) enum { value = val }
+#else
+    #define wxDEFINE_TEMPLATE_BOOL_VALUE(val) static const bool value = val
+#endif
+
+// Helper to decide if an object of type T is POD (Plain Old Data)
+template<typename T>
+struct wxIsPod
+{
+    wxDEFINE_TEMPLATE_BOOL_VALUE(false);
+};
+
+// Macro to add wxIsPod<T> specialization for given type that marks it
+// as Plain Old Data:
+#define WX_DECLARE_TYPE_POD(type)                           \
+    template<> struct wxIsPod<type>                         \
+    {                                                       \
+        wxDEFINE_TEMPLATE_BOOL_VALUE(true);                 \
+    };
+
+WX_DECLARE_TYPE_POD(bool)
+WX_DECLARE_TYPE_POD(unsigned char)
+WX_DECLARE_TYPE_POD(signed char)
+WX_DECLARE_TYPE_POD(unsigned int)
+WX_DECLARE_TYPE_POD(signed int)
+WX_DECLARE_TYPE_POD(unsigned short int)
+WX_DECLARE_TYPE_POD(signed short int)
+WX_DECLARE_TYPE_POD(signed long int)
+WX_DECLARE_TYPE_POD(unsigned long int)
+WX_DECLARE_TYPE_POD(float)
+WX_DECLARE_TYPE_POD(double)
+WX_DECLARE_TYPE_POD(long double)
+#if wxWCHAR_T_IS_REAL_TYPE
+WX_DECLARE_TYPE_POD(wchar_t)
+#endif
+#ifdef wxLongLong_t
+WX_DECLARE_TYPE_POD(wxLongLong_t)
+WX_DECLARE_TYPE_POD(wxULongLong_t)
+#endif
+
+// Visual C++ 6.0 can't compile partial template specializations and as this is
+// only an optimization, we can live with pointers not being recognized as
+// POD types under VC6
+#if !defined(__VISUALC__) || wxCHECK_VISUALC_VERSION(7)
+
+// pointers are Plain Old Data:
+template<typename T>
+struct wxIsPod<T*>
+{
+    static const bool value = true;
+};
+
+template<typename T>
+struct wxIsPod<const T*>
+{
+    static const bool value = true;
+};
+
+#endif // !VC++ < 7
+
+#endif // _WX_META_POD_H_