soapyigu · April 28, 2018 22:00
diff --git a/cast.m b/cast.m
 int main(int argc, const char * argv[]) {
    @autoreleasepool {
      
        Queue<Sub *> *subQueue = [[Queue alloc] init];
        Queue<Sup *> *supQueue = subQueue; // Warning: Incompatible pointer types initializing 'Queue<Base *>' with an expression of type 'Queue<Sub *>'
        
        [supQueue enqueue:[Sub new]];
    }
  
    return 0;
 }
	int main(int argc, const char * argv[]) {
	@autoreleasepool {

	Queue<Sub > subQueue = [[Queue alloc] init];
	Queue<Sup > supQueue = subQueue; // Warning: Incompatible pointer types initializing 'Queue<Base >' with an expression of type 'Queue<Sub >'

	[supQueue enqueue:[Sub new]];
	}

	return 0;
	}