| libstdc++
    | 
| Classes | |
| struct | std::equal_to< _Tp > | 
| struct | std::greater< _Tp > | 
| struct | std::greater_equal< _Tp > | 
| struct | std::less< _Tp > | 
| struct | std::less_equal< _Tp > | 
| struct | std::not_equal_to< _Tp > | 
The library provides six wrapper functors for all the basic comparisons in C++, like <.