On 1 February 2017 at 13:49, Mason wrote: > Hello, > > https://gcc.gnu.org/gcc-5/porting_to.html states > > "Typically, this macro is used as in the following: > > #if !defined __STDC_VERSION__ || __STDC_VERSION__ < 199901L > /* ... */ > #else > # include <stdint.h> > #endif > " > > I think it is unnecessary to test for the existence of __STDC_VERSION__ > because N1256 6.10.1p4 states > "all remaining identifiers [...] are replaced with the pp-number 0" > > Therefore > #if __STDC_VERSION__ < 199901L > would work as expected, even when __STDC_VERSION__ is undefined. > (As the constant-expression would be false.) But you'd get a warning with -Wundef
