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#pragma once
#include <type_traits>
/** MapFindPtr usage:
if (T* value = MapFindPtr(myMap, someKey) {
Cout << *value;
}
*/
template <class Map, class K>
inline auto MapFindPtr(Map& map, 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, 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) {
return MapFindPtr(static_cast<Derived&>(*this), key);
}
template <class K>
inline auto FindPtr(const K& key) const {
return MapFindPtr(static_cast<const Derived&>(*this), key);
}
template <class K, class DefaultValue>
inline auto Value(const K& key, const DefaultValue& defaultValue) const -> std::remove_reference_t<decltype(*this->FindPtr(key))> {
if (auto found = FindPtr(key)) {
return *found;
}
return defaultValue;
}
template <class K, class V>
inline const V& ValueRef(const K& key, V& defaultValue) const {
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) const = delete;
};
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