intial commit

source/mijin/container/map_view.hpp

@@ -0,0 +1,90 @@
+
+#pragma once
+
+#if !defined(MIJIN_CONTAINER_MAP_VIEW_HPP_INCLUDED)
+#define MIJIN_CONTAINER_MAP_VIEW_HPP_INCLUDED 1
+
+#include <unordered_map>
+
+namespace mijin
+{
+
+//
+// public defines
+//
+
+//
+// public constants
+//
+
+//
+// public types
+//
+
+template<typename TKey, typename TValue, typename TMap = std::unordered_map<TKey, TValue>>
+struct MapView
+{
+private:
+    TMap& map;
+public:
+    MapView() = delete;
+    MapView(const MapView&) = default;
+    MapView(MapView&&) noexcept = default;
+    inline MapView(TMap& map_) : map(map_) {}
+
+    MapView& operator=(const MapView&) = default;
+    MapView& operator=(MapView&&) noexcept = default;
+    
+    [[nodiscard]] TValue& operator[](const TKey& key)
+    {
+        return at(key);
+    }
+    [[nodiscard]] const TValue& operator[](const TKey& key) const
+    {
+        return at(key);
+    }
+
+    [[nodiscard]] TValue& at(const TKey& key)
+    {
+        return map.at(key);
+    }
+
+    [[nodiscard]] const TValue& at(const TKey& key) const
+    {
+        return map.at(key);
+    }
+
+    [[nodiscard]] auto begin() const
+    {
+        return map.begin();
+    }
+
+    [[nodiscard]] auto begin()
+    {
+        return map.begin();
+    }
+
+    [[nodiscard]] auto end()
+    {
+        return map.end();
+    }
+    
+    [[nodiscard]] auto end() const
+    {
+        return map.end();
+    }
+};
+
+// template<typename TKey, typename TValue, template<typename, typename, typename...> typename TMap>
+// MapView(TMap<TKey, TValue>& map) -> MapView<TKey, TValue, TMap<TKey, TValue>>;
+
+template<typename TMap>
+MapView(TMap& map) -> MapView<typename TMap::key_type, typename TMap::mapped_type, TMap>;
+
+//
+// public functions
+//
+
+} // namespace mijin
+
+#endif // !defined(MIJIN_CONTAINER_MAP_VIEW_HPP_INCLUDED)