Today I found the following:

#include <stdio.h>

int main(){
char x = 255;
int z = ((int)x)*2;

printf("%d\n", z); //prints -2

return 0;

}

So basically I'm getting an overflow because the size limit is determined by the operands on the right side of the = sign??

Why doesn't casting it to int before multiplying work?

In this case I'm using a char and int, but if I use "long" and "long long int" (c99), then I get similar behaviour. Is it generally advised against doing arithmetic with operands of different sizes?