Blocks.m

#!/usr/bin/env objc-run

@import Foundation;

@interface NSBlock // bite me
@end

@implementation NSBlock (invoke)
- (void) invoke
{
    ((void (^)(void))self)();
}
@end

int main() {
    void (^foo)(void) = ^{ NSLog(@"yolo"); };
    void (^bar)(void) = nil;
    
    foo();
    bar(); // <- this crashes
    
    [foo invoke];
    [bar invoke]; // <- this doesn’t
}

That's clever!