Complete example/test program for quick and dirty function to determine if a method in an Objective-C protocol is required or optional. Example for my answer to this stackoverflow question: http://stackoverflow.com/questions/14043930/how-to-identify-a-protocol-method-is-optional-during-runtime/14044086#14044086

MethodInProtocolsRequiredExample.m

#import <Foundation/Foundation.h>
#import <objc/runtime.h>

@protocol TestProtocol <NSObject>
@required
- (void)methodA;
@optional
- (void)methodB;
@end

@interface TestProtocolClass : NSObject <TestProtocol> @end

@implementation TestProtocolClass

- (void)methodA
{
  NSLog(@"%s", __PRETTY_FUNCTION__);
}

@end

BOOL MethodInProtocolIsRequired(Protocol *protocol, SEL methodSelector)
{
	struct objc_method_description methodDesc = protocol_getMethodDescription(protocol, methodSelector, YES, YES);
	return methodDesc.name != NULL;
}

int main(int argc, const char * argv[])
{
	@autoreleasepool {
		Protocol *p = objc_getProtocol("TestProtocol");
		BOOL methodAIsRequired = MethodInProtocolIsRequired(p, @selector(methodA));
		BOOL methodBIsRequired = MethodInProtocolIsRequired(p, @selector(methodB));
		NSLog(@"methodA is required? %i methodB is required? %i", methodAIsRequired, methodBIsRequired);
	}
    return 0;
}