* Purpose: Various preprocessor helpers
* Author: Vadim Zeitlin
* Created: 2006-09-30
- * RCS-ID: $Id$
* Copyright: (c) 2006 Vadim Zeitlin <vadim@wxwindows.org>
* Licence: wxWindows licence
*/
#ifndef _WX_CPP_H_
#define _WX_CPP_H_
+#include "wx/compiler.h" /* wxCHECK_XXX_VERSION() macros */
+
/* wxCONCAT works like preprocessor ## operator but also works with macros */
#define wxCONCAT_HELPER(text, line) text ## line
-#define wxCONCAT(text, line) wxCONCAT_HELPER(text, line)
-#define wxCONCAT3(x1, x2, x3) wxCONCAT(wxCONCAT(x1, x2), x3)
-#define wxCONCAT4(x1, x2, x3, x4) wxCONCAT(wxCONCAT3(x1, x2, x3), x4)
-#define wxCONCAT5(x1, x2, x3, x4, x5) wxCONCAT(wxCONCAT4(x1, x2, x3, x4), x5)
+#define wxCONCAT(x1, x2) \
+ wxCONCAT_HELPER(x1, x2)
+#define wxCONCAT3(x1, x2, x3) \
+ wxCONCAT(wxCONCAT(x1, x2), x3)
+#define wxCONCAT4(x1, x2, x3, x4) \
+ wxCONCAT(wxCONCAT3(x1, x2, x3), x4)
+#define wxCONCAT5(x1, x2, x3, x4, x5) \
+ wxCONCAT(wxCONCAT4(x1, x2, x3, x4), x5)
+#define wxCONCAT6(x1, x2, x3, x4, x5, x6) \
+ wxCONCAT(wxCONCAT5(x1, x2, x3, x4, x5), x6)
+#define wxCONCAT7(x1, x2, x3, x4, x5, x6, x7) \
+ wxCONCAT(wxCONCAT6(x1, x2, x3, x4, x5, x6), x7)
+#define wxCONCAT8(x1, x2, x3, x4, x5, x6, x7, x8) \
+ wxCONCAT(wxCONCAT7(x1, x2, x3, x4, x5, x6, x7), x8)
+#define wxCONCAT9(x1, x2, x3, x4, x5, x6, x7, x8, x9) \
+ wxCONCAT(wxCONCAT8(x1, x2, x3, x4, x5, x6, x7, x8), x9)
/* wxSTRINGIZE works as the preprocessor # operator but also works with macros */
#define wxSTRINGIZE_HELPER(x) #x
*/
#define wxEMPTY_PARAMETER_VALUE /* Fake macro parameter value */
+/*
+ Helpers for defining macros that expand into a single statement.
+
+ The standatd solution is to use "do { ... } while (0)" statement but MSVC
+ generates a C4127 "condition expression is constant" warning for it so we
+ use something which is just complicated enough to not be recognized as a
+ constant but still simple enough to be optimized away.
+
+ Another solution would be to use __pragma() to temporarily disable C4127.
+
+ Notice that wxASSERT_ARG_TYPE in wx/strvargarg.h relies on these macros
+ creating some kind of a loop because it uses "break".
+ */
+#ifdef __WATCOMC__
+ #define wxFOR_ONCE(name) for(int name=0; name<1; name++)
+ #define wxSTATEMENT_MACRO_BEGIN wxFOR_ONCE(wxMAKE_UNIQUE_NAME(wxmacro)) {
+ #define wxSTATEMENT_MACRO_END }
+#else
+ #define wxSTATEMENT_MACRO_BEGIN do {
+ #define wxSTATEMENT_MACRO_END } while ( (void)0, 0 )
+#endif
+
/*
Define __WXFUNCTION__ which is like standard __FUNCTION__ but defined as
NULL for the compilers which don't support the latter.
#endif
#endif /* __WXFUNCTION__ already defined */
+
+/* Auto-detect variadic macros support unless explicitly disabled. */
+#if !defined(HAVE_VARIADIC_MACROS) && !defined(wxNO_VARIADIC_MACROS)
+ /* Any C99 or C++11 compiler should have them. */
+ #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \
+ (defined(__cplusplus) && __cplusplus >= 201103L)
+ #define HAVE_VARIADIC_MACROS
+ #elif wxCHECK_GCC_VERSION(3,0)
+ #define HAVE_VARIADIC_MACROS
+ #elif wxCHECK_VISUALC_VERSION(8)
+ #define HAVE_VARIADIC_MACROS
+ #elif wxCHECK_WATCOM_VERSION(1,2)
+ #define HAVE_VARIADIC_MACROS
+ #endif
+#endif /* !HAVE_VARIADIC_MACROS */
+
+
+
+#ifdef HAVE_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_(args) wxCALL_FOR_EACH_ARG_N 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, args) \
+ wxCONCAT(wxCALL_FOR_EACH_, N) 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 /* HAVE_VARIADIC_MACROS */
+
#endif /* _WX_CPP_H_ */
projects / wxWidgets.git / blobdiff