A sign in C++ I've never seen before: |=

Question

I have some code here:

case MONITORTYPE_WUXGA_SXGA_WXGA:
    bResult |= (var == enum1);
    bResult |= (var == enum2);

Now i know what its doin

Answer 1

For most binary operators ♢ in C++ (except comparison operators, relational operators and boolean operators), there exists a corresponding compound assignment operator, ♢=.

That is, |= is simply the compound assignment operator for | which is bitwise or. Its use is completely equivalent to +=, *= etc. So

a |= b;
// is equivalent to
a = a | b;