A small C and C++ preprocessor library to suppress warnings without compromising backward compatibility.
by David Krauss (potatoswatter)
Compilers, particularly Clang, implement ever-more warnings as friendly reminders to follow good coding practices. Sometimes warnings are spurious and they must be silenced in particular instances.
There is a #pragma directive to do so, but it generates another warning if the compiler simply doesn't implement the warning.
Clang offers a __has_warning macro to avoid this issue, but then you also need to check that __has_warning exists… it gets complicated.
With this library, if you wanted to write char q = { 800 }; in C++, you can suppress the two resulting diagnostic messages like so:
// Specify the warning flag by defining the SUPPRESS_WARNING macro.
#define SUPPRESS_WARNING "-Wnarrowing"
// Include the header to suppress the warning and un-define the SUPPRESS_WARNING parameter.
#include "suppress_warning.h"
// Warning suppressions may be nested.
#define SUPPRESS_WARNING "-Wconstant-conversion"
#include "suppress_warning.h"
char q = { 800 }; // Do dastardly deeds without reprimand.
// Re-enable warnings when finished.
#include "unsuppress_warning.h"
#include "unsuppress_warning.h"
Unfortunately, GCC does not yet implement __has_warning. Anticipating that it will, this library is coded for forward compatibility.
Until then, only Clang is supported and warnings are not suppressed on GCC.