On [cppreference](http://en.cppreference.com/w/cpp/container/map/emplace_hint) about [`map::emplace_hint()`](http://en.cppreference.com/w/cpp/container/map/emplace_hint):

> 
> 
> ```c++
> template <class... Args>
> iterator emplace_hint( const_iterator hint, Args&&... args );
> 
> ```
> 
> Inserts a new element to the container, using `hint` as a suggestion where the element should go.
> 
> 
> 

So if it is a suggestion does that mean that the implementation doesn't *have* to place the element there? What exactly is a hint?