(C++) Adapter

An adapter is a type of functor that allows a method or a pointer to a function to be used as an argument to algorithms [1].

Most adapters can be found in the header file functional.

There are four types of adapters [1]:

• Binder: allows a two-argument function object to be used as a single-argument function by binding one argument to a value
• Member function adapter: allows a member function to be used as an argument to algorithms
• Pointer to function adapter: allows a pointer-to-function to be used as an argument to algorithms
• Negater: allows to express the opposite of a predicate

STL and Boost adapters

One can distinguish STL and Boost adapters by their namespace: All STL objects are in namespace std. All Boost objects are in namespace boost.

• Binders
  • std::bind1st
  • std::bind2nd
  • boost::bind
• Member function adapters
  • std::mem_fun
  • std::mem_fun_ref
  • boost::mem_fn
• Pointer to function adapter
  • std::ptr_fun
• Negaters
  • std::not1
  • std::not2

References

• [1] Bjarne Stroustrup. The C++ Programming Language (3rd edition). 1997. ISBN: 0-201-88954-4. Chapter 18.4.4: 'A member function adapter allows a member function to be used as an argument to algorithms. A pointer to function adapter allows a pointer to a function to be used as an argument to algorithms.'