老师，最新在用swift做一个项目，swift有没有类似objective-c的这种简便写法，gcc的扩展，搜索了找了半天没找到
[self addSubview:({
            _coverView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, frame.size.width, frame.size.height - GTVideoToolbarHeight)];
            _coverView;
        })];