std::map find_if condition style confusion

Question

I\'d like to use std::find_if to search for the first element in my map that has a certain value in a specific element of its value structure. I\'m a little confus

Answer 1

struct Pred
{
    Pred(int x) : x_(x) { }
    bool operator()(const std::pair& p)
    {
        return (x_ == p.second.x);
    }
private:
    int x_;
};

... = std::find_if(myMap.begin(), myMap.end(), Pred(NUMBER));