Why does the standard library have find and find_if?

Question

Couldn\'t find_if just be an overload of find? That\'s how std::binary_search and friends do it...

Answer 1

You can certainly implement find in terms of find_if using some sort of equality predicate.

I would guess that the real reason is that you can implement find fairly easily and provide performant specialised implementations for typical encountered types; if you are using find_if, the predicate you pass in can be arbitrarily complex, which gives the library implementer less scope of optimisation.

Also, C++ has the philosphy of "you don't pay for what you don't use" and you'd normally expect that you don't want to pay for a predicate evaluation if a simple comparison will do.