libstdc++

Classes  
struct  std::divides< _Tp > 
struct  std::minus< _Tp > 
struct  std::modulus< _Tp > 
struct  std::multiplies< _Tp > 
struct  std::negate< _Tp > 
struct  std::plus< _Tp > 
Because basic math often needs to be done during an algorithm, the library provides functors for those operations. See the documentation for the base classes for examples of their use.