C++ meaning |= and &=

Question

I have a part of code that contains the following functions:

void Keyboard(int key)
{
    switch (key) {
    case GLFW_KEY_A: m_controlState |= TDC_LEFT; bre         


        

Answer 1

x |= y specifically turns on (sets to 1) those bits in x present in y, leaving all the others in x as they were.

x &= ~y specifically turns off (sets to 0) those bits in x present in y, leaving all the others in x as they were.