add settings reset

libs/include/entt/meta/context.hpp

@@ -0,0 +1,51 @@
+#ifndef ENTT_META_CTX_HPP
+#define ENTT_META_CTX_HPP
+
+#include "../container/dense_map.hpp"
+#include "../core/fwd.hpp"
+#include "../core/utility.hpp"
+
+namespace entt {
+
+class meta_ctx;
+
+/*! @cond TURN_OFF_DOXYGEN */
+namespace internal {
+
+struct meta_type_node;
+
+struct meta_context {
+    dense_map<id_type, meta_type_node, identity> value{};
+
+    [[nodiscard]] inline static meta_context &from(meta_ctx &ctx);
+    [[nodiscard]] inline static const meta_context &from(const meta_ctx &ctx);
+};
+
+} // namespace internal
+/*! @endcond */
+
+/*! @brief Disambiguation tag for constructors and the like. */
+class meta_ctx_arg_t final {};
+
+/*! @brief Constant of type meta_context_arg_t used to disambiguate calls. */
+inline constexpr meta_ctx_arg_t meta_ctx_arg{};
+
+/*! @brief Opaque meta context type. */
+class meta_ctx: private internal::meta_context {
+    // attorney idiom like model to access the base class
+    friend struct internal::meta_context;
+};
+
+/*! @cond TURN_OFF_DOXYGEN */
+[[nodiscard]] inline internal::meta_context &internal::meta_context::from(meta_ctx &ctx) {
+    return ctx;
+}
+
+[[nodiscard]] inline const internal::meta_context &internal::meta_context::from(const meta_ctx &ctx) {
+    return ctx;
+}
+/*! @endcond */
+
+} // namespace entt
+
+#endif