From f81f34e6fa47471f47fd42709faaa48a45ec25f8 Mon Sep 17 00:00:00 2001
From: skypjack <michele.caini@gmail.com>
Date: Thu, 15 Jan 2026 15:08:51 +0100
Subject: [PATCH] entity: constrained type instead of sfinae based design for
 traits

---
 src/entt/entity/entity.hpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/entt/entity/entity.hpp b/src/entt/entity/entity.hpp
index 5dc32b72f..f17e96e9b 100644
--- a/src/entt/entity/entity.hpp
+++ b/src/entt/entity/entity.hpp
@@ -14,17 +14,20 @@ namespace entt {
 /*! @cond TURN_OFF_DOXYGEN */
 namespace internal {
 
-template<typename, typename = void>
+template<typename>
 struct entt_traits;
 
 template<typename Type>
-struct entt_traits<Type, std::enable_if_t<std::is_enum_v<Type>>>
-    : entt_traits<std::underlying_type_t<Type>> {
+    requires std::is_enum_v<Type>
+struct entt_traits<Type>: entt_traits<std::underlying_type_t<Type>> {
     using value_type = Type;
 };
 
 template<typename Type>
-struct entt_traits<Type, std::enable_if_t<std::is_class_v<Type>>>
+    requires requires { typename Type::entity_type; }
+             && std::convertible_to<Type, typename Type::entity_type>
+             && std::constructible_from<Type, typename Type::entity_type>
+struct entt_traits<Type>
     : entt_traits<typename Type::entity_type> {
     using value_type = Type;
 };