Objective-C ProtocolContainsInstanceSelector

gistfile1.m

BOOL ProtocolContainsInstanceSelector(NSString *protocolName, SEL sel);
BOOL ProtocolContainsInstanceSelector(NSString *protocolName, SEL sel)
{
    Protocol *p = objc_getProtocol([protocolName cStringUsingEncoding:NSUTF8StringEncoding]);

    // must check for both required = {YES, NO}
    struct objc_method_description desc = protocol_getMethodDescription(p, sel, YES, YES);
    BOOL contains = desc.name != NULL && desc.types != NULL;

    if (!contains) {
        desc = protocol_getMethodDescription(p, sel, NO, YES);
        contains = desc.name != NULL && desc.types != NULL;
    }

    return contains;
}