初始化内容

third/LuaBridge3/Source/LuaBridge/detail/Enum.h

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+// https://github.com/kunitoki/LuaBridge3
+// Copyright 2023, kunitoki
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "Config.h"
+#include "Errors.h"
+#include "LuaHelpers.h"
+#include "Stack.h"
+
+#include <type_traits>
+
+namespace luabridge {
+
+//=================================================================================================
+/**
+ * @brief LuaBridge enum wrapper for enums as integers.
+ *
+ * An enum exposed with this class will just be decayed to lua as integer. It's responsibility of
+ * the developer to make sure that a lua integer could be converted back to C++. Failing to validate a lua
+ * integer before converting to the corresponding C++ enum value could lead to a C++ enum that has no defined value.
+ *
+ * For improved security, specify which values the enum will have, so runtime validation could be performed.
+ */
+template <class T, T... Values>
+struct Enum
+{
+    static_assert(std::is_enum_v<T>);
+
+    using Type = std::underlying_type_t<T>;
+
+    [[nodiscard]] static Result push(lua_State* L, T value)
+    {
+        return Stack<Type>::push(L, static_cast<Type>(value));
+    }
+
+    [[nodiscard]] static TypeResult<T> get(lua_State* L, int index)
+    {
+        const auto result = Stack<Type>::get(L, index);
+        if (! result)
+            return result.error();
+
+        if constexpr (sizeof...(Values) > 0)
+        {
+            constexpr Type values[] = { static_cast<Type>(Values)... };
+            for (std::size_t i = 0; i < sizeof...(Values); ++i)
+            {
+                if (values[i] == *result)
+                    return static_cast<T>(*result);
+            }
+
+            return makeErrorCode(ErrorCode::InvalidTypeCast);
+        }
+        else
+        {
+            return static_cast<T>(*result);
+        }
+    }
+
+    [[nodiscard]] static bool isInstance(lua_State* L, int index)
+    {
+        return lua_type(L, index) == LUA_TNUMBER;
+    }
+};
+
+} // namespace luabridge