It’s no good doing sth中的good是什么词性

1.《朗文当代英语词典》认为这样用的 good 是名词，该词典在其名词用法下用黑体字给出了以下固定搭配：it's no good (doing sth)。其相关例句为：

It's no good telling him—he won't listen.

2.《柯林斯高级英语学习词典》也认为这样用的 good 是名词，该词典在第12条的名词用法下给出的解释是：If you say that doing something is no good or does not do any good, you mean that doing it is not of any use or will not bring any success. 相应的例句是：

It's no good worrying about it now.