Question

What do the |=, &= and ~ do?

mode |= MyEnum.ROTATE;
mode &= ~MyEnum.RESHAPE;

Update:

Many of the answers simply said their bitwise this and bitwise that which did not help since i did not know what bitwise meant. Here’s a good intro.

Answer 1

Those are bitwise operations.

mode |= MyEnum.ROTATE

is the same as

mode = mode | MyEnum.ROTATE

or in other words we are adding ROTATE to the mode.

The secone example removes RESHAPE from the mode

mode is a bitmask