[Bug c++/48379] -Wdouble-promotion warns for promotion by varargs

[adam.f.badura at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48379

Adam Badura <adam.f.badura at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |adam.f.badura at gmail dot com

--- Comment #6 from Adam Badura <adam.f.badura at gmail dot com> ---
To help others who might get here like I did, if you are using macros for
logging/printing (that eventually call printf-like functions) or are willing to
use them, _Pragma could be used to silence the warning "locally", like this
(https://godbolt.org/z/5oYPhjen9):

#include <cstdio>

#define LOG(fmt, ...) \
    _Pragma("GCC diagnostic push")  \
    _Pragma("GCC diagnostic ignored \"-Wdouble-promotion\"") \
    std::printf(fmt, __VA_ARGS__); \
    _Pragma("GCC diagnostic pop")  \


void test(float f)
{
    LOG("%f", f);
}