C++ returning an assignment?

Question

In C++ what does it mean when a function returns an assignment? e.g.

int a = ...;
int b = ...;
int some_function(p)
{
    return a = b;
}

Answer 1

In this case it performs the assignment, then returns b.

This sort of stuff might get flagged by the compiler as an inadvertent bug, usually you'd mean a == b, so you may need to deal with that. Doing it as a separate line makes it clear it's intentional.