static std::pair<int, int> hit(const boost::unordered_map<int, double> &real, const boost::unordered_map<int, double> &fake, double thres = 0.0) { int a = 0, b = 0; for (auto it = fake.cbegin(); it != fake.cend(); ++it) { if (it->second >= thres) { ++b; if (real.end() != real.find(it->first)) ++a; } } return std::make_pair(a, b); }