On 21 January 2018 at 07:12, Jay K wrote: > extern const int foo = 123; > > > > Why does this warn? > This is a valid portable form, with the same meaning > across all compilers, and, importantly, portably > to C and C++. > > I explicitly do not want to say: > > const int foo = 123 > > because I want the code to be valid and have the same meaning > in C and C++ (modulo name mangling). > > I end up with: > > // Workaround gcc warning. > #ifdef __cplusplus > #define EXTERN_CONST extern const > #else > #define EXTERN_CONST const > #endif > > > EXTERN_CONST int foo = 123; > > and having to explain it to people.
Why not simply: extern const int foo; const int foo = 123; without the ugly macro? Or, according to taste: // Without an extern declaration, file-scope const variables are static: extern const int foo; const int foo = 123; Or: #ifdef __cplusplus // Without an extern declaration, file-scope const variables are static: extern const int foo; #endif const int foo = 123; But your macro version is just ugly. And instead of complaining that you have to explain it to people, why not explain it with a comment in the code? That's what comments are for.
