Has include macro

Has include Macro

Config: TPP_CONFIG_HAVE___has_include
Check: #if defined(__has_include), #if defined(__has_include_next)
Function: tpp.c: TPPLexer_Next
Known supporting compilers: clang

Two builtin macros, that can be used, to check if a #include or #include_next directive is allowed.

Syntax: __has_include(<sys-include-string>) / __has_include("include-string")

The following shows a usage example, to check for a include file:

#if __has_include(<stdio.h>)
#include <stdio.h>
#else
#warning Missing <stdio.h>!
#endif

s.a. [Include directive]