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

Not directly, but Boost.Bind has a more powerful capability that can be used for this application. If, for the bound function, a pointer to member is provided, Boost.Bind will create a functor that takes a pointer to the class and returns a reference to the member. In your case, something like equal(m.begin(), m.end(), bind(std::equal_to<string>(), _1, bind(&map_type::value_type::first, _1))); At 03:55 PM 11/9/2006, you wrote:

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 >(_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...

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