The pair2params() function allows you to use a more readable predicate for iterating over std::map's without having to define a custom algorithm. The first argument will "bind" to pair.first and the second argument to pair.second.

pair2params.hpp

#include <map>
#include <utility>
#include <iostream>
#include <algorithm>

using namespace std;


namespace {

    auto pair2params = [](auto&& f)
    {
    	return [f](auto&& p) {
    		f(p.first, p.second);
    	};
    };

}


int main()
{
    auto values = map<int, string>{
        {0, "hello"},
        {1, "world!"}
    };
    
    for_each(begin(values), end(values), pair2params([](int i, const string& s) {
        cout << i << ": " << s << endl;
    });
}