What is a candidate function? What is a viable function?

什么是候选函数？什么是可行函数？

youdao

The match for each argument is no worse than the match required by any other viable function.

其每个实参的匹配都不劣于其他可行函数需要的匹配。

youdao

This call is therefore ambiguous: Each viable function is a better match on one of the arguments to the call.

因此，这个调用有二义性：每个可行函数都对函数调用的一个实参实现更好的匹配。

youdao

Dr Shinichi Matsumoto and colleagues said islets from living donors have the advantage of being more viable and more likely to function properly.

BBC: Many people with diabetes must have regular insulin shots