Question

Assuming we have 32bit integer, 8bit char, gcc compiler and Intel architecture:

What would be the fastest way (with no assembler usage) to extract, say, third octet of integer variable? To store it to a char of some specific place of char[] for example?

Answer 1

use a Union:

union myCharredInt
{
    int myInt;
    struct {
        char char1;
        char char2;
        char char3;
        char char4;
    }
};

myCharredInt a = 5;

char c = a.char3;