find in std::vector<std::pair>

I have a vector of pairs. The first in the pair is of type std::string and the second is of type Container.

What convenient functionality exists in std or boost so that I can return a Container given the string value as key?

UPDATE

It has been commented that I could use a std::map instead, but I actually need to preserve the order of my items, in the order that I push them to the vector.