More information on `({});` in C?

Question

I\'ve noticed that sometimes, C macros are written as something like this:

#define foo(bar) ({ ++bar; })

After some experimentation, I\'ve

Answer 1

The cool thing about statement expressions (if there is a cool thing) is that the last statement is the result of the expression.

#define foo(bar) ({ ++bar; 3.1415927; })

int i = 0;
float pi = foo(i);