Method deref

3rdparty/lua/sol/sol.hpp:10344–10346

		}

		void deref(lua_State* L_) const noexcept {
			luaL_unref(L_, LUA_REGISTRYINDEX, ref);
		}

		stateless_reference copy(lua_State* L_) const noexcept {
			if (!valid(L_)) {