What is the function of “(void) (&_min1 == &_min2)” in the min macro in kernel.h?

Question

In kernel.h min is defined as:

#define min(x, y) ({                \\
    typeof(x) _min1 = (x);          \\
    typeof(y) _min2 = (y);          \\
    (void         


        

Answer 1

See http://www.osnews.com/comments/20566 which explains:

It has to do with typechecking.

Making a simple program:

int x = 10; 
long y = 20; 
long r = min(x, y); 

Gives the following warning: warning: comparison of distinct pointer types lacks a cast