A relatively simple function for selectively removing members of a std::map container.

map_remove_if.cpp

#include <functional>
#include <map>

//this function takes "key, value" types of the map container as template parameters
//this function takes the map container and a lambda as arguments
//the lambda takes one argument, a std::pair structure which in turn takes "const key, const& value" as it's template parameters

template<typename key, typename value>
void map_remove_if(std::map<key, value>& container, std::function<bool(std::pair<key const, value const&>)> fn) {
	std::map<key, value>::iterator it = container.begin();
	while(it != container.end()) {
		if (fn(*it)) {
			it = container.erase(it);
		}
		else {
			++it;
		}
	}
}