[Boost-users] comparing map's key and sorted vector

From: Maitre Bart (maitrebart_at_[hidden])
Date: 2006-11-09 16:55:33

Suppose I have a map (m) and a sorted vector of strings (v).
The map's key is a string, and the map's value is foobar.

I wish to compare map's keys with the vector's values and detect if they all 
match:

(*mit).first == *vit

and wish to do it with STL/Boost algo and functors.

So I am starting with this:

equal(m.begin(), 
      m.end(), 
      v.begin(),
      boost::bind(std::equa_to<string>(),
                  std::select1st<std::pair<string,foobar> >(_1), _2));

I know 2 parameters are past to bind: *mit and *vit . However, before the 
equality, I want to extract the key from the map iterator (i.e. (*mit).first) 
before the comparison. That is this part I have difficulty to concretise.

Btw, is there any equivalent to select1st (SGI extension) in Boost?

Does anyone have any idea?
I must be close to the solution...