Question

Possible Duplicate:
Return value from local scope?

#include <stdio.h>

int main() {
        int x = ({int a = 2; a;});
        printf("%d\n", x);
}

Output: 2

Answer 1

It’s a non-standard extension to the C/C++ languages provided by GCC called statement expressions. If you attempt to compile with the -pedantic flag, you’ll get the warning “ISO C forbids braced-groups within expressions”. It is not portable code and should be avoided if possible.