Is there a standard C++ function object for taking apart a std::pair?

Question

Does anyone know if there\'s a de-facto standard (i.e., TR1 or Boost) C++ function object for accessing the elements of a std::pair? Twice in the past 24 hours I\'ve wished

Answer 1

Take a look at boost::adaptors. There are predefined adaptors for iterating over map keys or values without copying them to an intermediate container.