#pragma once #include <util/system/compiler.h> #include <type_traits> #include <utility> /** MapFindPtr usage: if (T* value = MapFindPtr(myMap, someKey) { Cout << *value; } */ template <class Map, class K> inline auto MapFindPtr(Map& map Y_LIFETIME_BOUND, const K& key) { auto i = map.find(key); return (i == map.end() ? nullptr : &i->second); } template <class Map, class K> inline auto MapFindPtr(const Map& map Y_LIFETIME_BOUND, const K& key) { auto i = map.find(key); return (i == map.end() ? nullptr : &i->second); } /** helper for THashMap/TMap */ template <class Derived> struct TMapOps { template <class K> inline auto FindPtr(const K& key) Y_LIFETIME_BOUND { return MapFindPtr(static_cast<Derived&>(*this), key); } template <class K> inline auto FindPtr(const K& key) const Y_LIFETIME_BOUND { return MapFindPtr(static_cast<const Derived&>(*this), key); } template <class K, class DefaultValue> inline auto Value(const K& key, DefaultValue&& defaultValue) const { auto found = FindPtr(key); return found ? *found : std::forward<DefaultValue>(defaultValue); } template <class K, class V> inline const V& ValueRef(const K& key, V& defaultValue Y_LIFETIME_BOUND) const Y_LIFETIME_BOUND { static_assert(std::is_same<std::remove_const_t<V>, typename Derived::mapped_type>::value, "Passed default value must have the same type as the underlying map's mapped_type."); if (auto found = FindPtr(key)) { return *found; } return defaultValue; } template <class K, class V> inline const V& ValueRef(const K& key, V&& defaultValue Y_LIFETIME_BOUND) const Y_LIFETIME_BOUND = delete; };