C11 _Generic: how to deal with string literals?

Question

Using the _Generic feature in C11, how do you deal with string literals?

For instance:

#include 
#define foo(x) _Generic(         


        

Answer 1

I have figured out a way to avoid using the clever (0,x) trick.

If you use a string literal the type is char[s] , where s is the size of the string literal.

How do you get that size?, use sizeof operator:

#include 

#define Test( x )   _Generic( ( x ) ,   char*: puts ,                   \
                                        const char*: puts ,             \
                                        const char[sizeof( x )]: puts , \
                                        char[sizeof( x )]: puts )( x )

int main(void) 
{

    char str[] = "This" ;
    Test( str ) ;

    Test( "works" ) ;

    char str2[10] = "!!!" ;
    Test( str2 ) ;

return 0;
}

I tried compiling it with clang and Pelles and it worked.

The only problem you still have to cast variable length arrays.

After trying some more I found another analogue way of doing what Pascal Cuoq did, use &* operators:

#include 
#define foo(x) _Generic( ( &*(x) ), char*: puts , const char*: puts )( x )

int main()
{
    foo("Hello, world!");
    return 0;
}