I know that this is a long time after the original query, but this may still be useful. This can be done in GCC using the stringify operator “#”, but it requires two stages. #define XSTR(x) STR(x) #define STR(x) #x The value of a macro can then be displayed with: #pragma message “The value of … Read more
As wrappers for debug functions, to automatically pass things like __FILE__, __LINE__, etc: #ifdef ( DEBUG ) #define M_DebugLog( msg ) std::cout << __FILE__ << “:” << __LINE__ << “: ” << msg #else #define M_DebugLog( msg ) #endif Since C++20 the magic type std::source_location can however be used instead of __LINE__ and __FILE__ to … Read more
You can use the Available tag, for example : @available(*, deprecated) func myFunc() { // … } Where * is the platform (iOS, iOSApplicationExtension, macOS, watchOS, tvOS, * for all, etc.). You can also specify the version of the platform from which it was introduced, deprecated, obsoleted, renamed, and a message : @available(iOS, deprecated:6.0) func … Read more
__FUNCTION__ is non standard, __func__ exists in C99 / C++11. The others (__LINE__ and __FILE__) are just fine. It will always report the right file and line (and function if you choose to use __FUNCTION__/__func__). Optimization is a non-factor since it is a compile time macro expansion; it will never affect performance in any way.
Think of some of the problems that can occur if there is no newline. According to the ANSI standard the #include of a file at the beginning inserts the file exactly as it is to the front of the file and does not insert the new line after the #include <foo.h> after the contents of … Read more
#if defined(CONDITION1) || defined(CONDITION2) should work. 🙂 #ifdef is a bit less typing, but doesn’t work well with more complex conditions
cl.exe, the command line interface to Microsoft Visual C++, has three different options for outputting the preprocessed file (hence the inconsistency in the previous responses about Visual C++): /E: preprocess to stdout (similar to GCC’s -E option) /P: preprocess to file /EP: preprocess to stdout without #line directives If you want to preprocess to a … Read more
C99 way, also supported by VC++ compiler. #define FOO(fmt, …) printf(fmt, ##__VA_ARGS__)
Simple as: #define GET_MACRO(_1,_2,_3,NAME,…) NAME #define FOO(…) GET_MACRO(__VA_ARGS__, FOO3, FOO2)(__VA_ARGS__) So if you have these macros, they expand as described: FOO(World, !) // expands to FOO2(World, !) FOO(foo,bar,baz) // expands to FOO3(foo,bar,baz) If you want a fourth one: #define GET_MACRO(_1,_2,_3,_4,NAME,…) NAME #define FOO(…) GET_MACRO(__VA_ARGS__, FOO4, FOO3, FOO2)(__VA_ARGS__) FOO(a,b,c,d) // expands to FOO4(a,b,c,d) Naturally, if you … Read more
If you use a C99 or later compiler #define debug_print(fmt, …) \ do { if (DEBUG) fprintf(stderr, fmt, __VA_ARGS__); } while (0) It assumes you are using C99 (the variable argument list notation is not supported in earlier versions). The do { … } while (0) idiom ensures that the code acts like a statement … Read more