using static System.Console;

void M(object o) {
    switch (o) {
        case (int) or string:
            WriteLine("OK");
            break;
    }
}

M(1);

error CS1001: Identifier expected
error CS1002: ; expected
error CS1513: } expected
error CS1513: } expected
error CS1022: Type or namespace definition, or end-of-file expected
error CS1022: Type or namespace definition, or end-of-file expected
error CS1022: Type or namespace definition, or end-of-file expected
error CS0103: The name 'or' does not exist in the current context
error CS0139: No enclosing loop out of which to break or continue
error CS8070: Control cannot fall out of switch from final case label ('case (int) or ')