Add wxCALL_FOR_EACH() macro.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72836 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Václav Slavík
2012-11-01 16:45:01 +00:00
parent 91578aec8d
commit a4d982a7cf

View File

@@ -101,5 +101,56 @@
#endif
#endif /* __WXFUNCTION__ already defined */
#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \
(defined(__cplusplus) && __cplusplus >= 201103L)
#define wxHAS_VARIADIC_MACROS
#elif defined(__GNUC__) && __GNUC__ >= 3
#define wxHAS_VARIADIC_MACROS
#elif defined(_MSC_VER) && _MSC_VER >= 1400
#define wxHAS_VARIADIC_MACROS
#endif
#ifdef wxHAS_VARIADIC_MACROS
/*
wxCALL_FOR_EACH(what, ...) calls the macro from its first argument, what(pos, x),
for every remaining argument 'x', with 'pos' being its 1-based index in
*reverse* order (with the last argument being numbered 1).
For example, wxCALL_FOR_EACH(test, a, b, c) expands into this:
test(3, a) \
test(2, b) \
test(1, c)
Up to eight arguments are supported.
(With thanks to https://groups.google.com/d/topic/comp.std.c/d-6Mj5Lko_s/discussion
and http://stackoverflow.com/questions/1872220/is-it-possible-to-iterate-over-arguments-in-variadic-macros)
*/
#define wxCALL_FOR_EACH_NARG(...) wxCALL_FOR_EACH_NARG_(__VA_ARGS__, wxCALL_FOR_EACH_RSEQ_N())
#define wxCALL_FOR_EACH_NARG_(...) wxCALL_FOR_EACH_ARG_N(__VA_ARGS__)
#define wxCALL_FOR_EACH_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, N, ...) N
#define wxCALL_FOR_EACH_RSEQ_N() 8, 7, 6, 5, 4, 3, 2, 1, 0
#define wxCALL_FOR_EACH_1(what, x) what(1, x)
#define wxCALL_FOR_EACH_2(what, x, ...) what(2, x) wxCALL_FOR_EACH_1(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_3(what, x, ...) what(3, x) wxCALL_FOR_EACH_2(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_4(what, x, ...) what(4, x) wxCALL_FOR_EACH_3(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_5(what, x, ...) what(5, x) wxCALL_FOR_EACH_4(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_6(what, x, ...) what(6, x) wxCALL_FOR_EACH_5(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_7(what, x, ...) what(7, x) wxCALL_FOR_EACH_6(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_8(what, x, ...) what(8, x) wxCALL_FOR_EACH_7(what, __VA_ARGS__)
#define wxCALL_FOR_EACH_(N, what, ...) \
wxCONCAT(wxCALL_FOR_EACH_, N)(what, __VA_ARGS__)
#define wxCALL_FOR_EACH(what, ...) \
wxCALL_FOR_EACH_(wxCALL_FOR_EACH_NARG(__VA_ARGS__), what, __VA_ARGS__)
#else
#define wxCALL_FOR_EACH Error_wx_CALL_FOR_EACH_requires_variadic_macros_support
#endif /* wxHAS_VARIADIC_MACROS */
#endif /* _WX_CPP_H_ */