It's totally legit to cull a function, get back a value, do nothing with it other than compare it to another value.

挑选一个函数是完全合法的，返回一个值，用它来做些事情而不是用它与其它的值比较。

哈佛公开课 - 计算机科学课程节选

The entire project yielded nothing of value, nothing for consumption or service.

FORBES: Inflation Destroys Real Wages

The delusion involved in the fourth myth may shock many - my computer contains nothing of value.

BBC: Computer security words in a Scrabble game

For the Saudis, its loss is a reminder of a problem that has been festering just across the Red Sea for some time: Somali analysts say that Saudi Arabia has made big promises of aid and assistance to Somalia, but has delivered nothing of value.

ECONOMIST: The significance of the latest attacks by Somali pirates