Problème dans la compréhension de la fonction décimale à la fonction binaire avec des opérateurs bitwises en C ++

fonction récursive xxx

exemple xxx

void function(unsigned int a);
//            ^^^^^^^^

// Step 1: You call a function defined as `void function(int a)`
// which accepts one parameter of type int and returns a void.
void function(int a)
{
    // Step 2: This function checks if a is zero or some other value. 
    // If it is zero, nothing happens and the function returns.
    // If it is non-zero, we proceed inside the if block.
    if(a){
        // Step 3: we do two things here.
        // First we right-shift whatever value is stored in a.
        // Right-shifting means if we have e.g. a=8, which is 1000 in binary,
        // then rightshifting 8 would be 0100 or 4. Basically it is division by 2.
        // This continues until we have 0000.

        // Secondly, this function will call itself then. This is called recursion.
        // So the "void function(4)-> void function(2) -> void function(1)" calls will run.
        function(a>>1);

        // Here we will bitwise AND with 1.
        // So, 0001 & 0001 = 1
        // 0010 & 0001 = 0
        // 0100 & 0001 = 0
        // 1000 & 0001 = 0
        // And this is what you will see on the terminal as output: 1000
        // The 1 gets printed first, because the inner most call in the recursion
        // finishes first and the call stack unwraps back up.
        cout<<(a&1);
    }
}