[boost] Re: functors for taking apart std::pair?

From: Edward Diener (eddielee_at_[hidden])
Date: 2003-07-10 07:29:10

Marshall Clow wrote:
> I recently had a need for a functor to return a component of a
> std::pair, and I was
> surprised to see that they didn't exist either in the standard
> library or in boost.

Matt Austern lists in his excellent book "Generic Programming and the STL"
the functors select1st and select2nd for getting a pair's "first" and
"second" members repsectively. His note to both says that they were in the
original HP STL and in the SGI STL although they are not present in the
current C++ Standard Library.