初始化内容

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

@@ -0,0 +1,77 @@
+// https://github.com/kunitoki/LuaBridge3
+// Copyright 2023, kunitoki
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "Config.h"
+#include "Stack.h"
+
+#include <optional>
+#include <type_traits>
+
+namespace luabridge {
+
+//=================================================================================================
+/**
+ * @brief Get a global value from the lua_State.
+ *
+ * @note This works on any type specialized by `Stack`, including `LuaRef` and its table proxies.
+*/
+template <class T>
+TypeResult<T> getGlobal(lua_State* L, const char* name)
+{
+    lua_getglobal(L, name);
+
+    auto result = luabridge::Stack<T>::get(L, -1);
+
+    lua_pop(L, 1);
+
+    return result;
+}
+
+//=================================================================================================
+/**
+ * @brief Try to get a field from a global table without creating a LuaRef.
+ *
+ * This is a fast-path helper for optional lookup patterns. It invokes normal Lua field access
+ * on the table, including metamethods, and returns std::nullopt when the global is not a table
+ * or the field cannot be converted to the requested type.
+ */
+template <class T>
+std::optional<T> tryGetGlobalField(lua_State* L, const char* globalName, const char* fieldName)
+{
+    const StackRestore stackRestore(L);
+
+    lua_getglobal(L, globalName);
+    if (! lua_istable(L, -1))
+        return std::nullopt;
+
+    lua_getfield(L, -1, fieldName);
+
+    auto result = Stack<std::decay_t<T>>::get(L, -1);
+    if (! result)
+        return std::nullopt;
+
+    return *result;
+}
+
+//=================================================================================================
+/**
+ * @brief Set a global value in the lua_State.
+ *
+ * @note This works on any type specialized by `Stack`, including `LuaRef` and its table proxies.
+ */
+template <class T>
+bool setGlobal(lua_State* L, T&& t, const char* name)
+{
+    if (auto result = push(L, std::forward<T>(t)))
+    {
+        lua_setglobal(L, name);
+        return true;
+    }
+
+    return false;
+}
+
+} // namespace luabridge