Is there a shorter way to write compound 'if' conditions? [duplicate]

Answer 1

If you need to check a character against an arbitrary set of characters, you could try writing this:

std::set allowed_chars = {'A', 'B', 'C', 'D', 'E', 'G', 'Q', '7', 'z'};
if(allowed_chars.find(ch) != allowed_chars.end()) {
    /*...*/
}