From 151f180199ccd760f8ce72bd23117a00f3b5cdc4 Mon Sep 17 00:00:00 2001
From: Michele Caini <michele.caini@gmail.com>
Date: Thu, 22 Jul 2021 18:08:19 +0200
Subject: [PATCH] core: make is_equality_comparable[_v] work with iterators
 (close #739)

---
 src/entt/core/type_traits.hpp  | 4 +++-
 test/entt/core/type_traits.cpp | 1 +
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/entt/core/type_traits.hpp b/src/entt/core/type_traits.hpp
index 01db08570..2192ec438 100644
--- a/src/entt/core/type_traits.hpp
+++ b/src/entt/core/type_traits.hpp
@@ -443,7 +443,9 @@ template<typename Type>
 template<typename Type>
 [[nodiscard]] constexpr auto is_equality_comparable(choice_t<1>)
 -> decltype(std::declval<typename Type::value_type>(), std::declval<Type>() == std::declval<Type>()) {
-    if constexpr(std::is_same_v<typename Type::value_type, Type>) {
+    if constexpr(is_iterator_v<Type>) {
+        return true;
+    } else if constexpr(std::is_same_v<typename Type::value_type, Type>) {
         return is_equality_comparable<Type>(choice<0>);
     } else {
         return is_equality_comparable<typename Type::value_type>(choice<2>);
diff --git a/test/entt/core/type_traits.cpp b/test/entt/core/type_traits.cpp
index 0329d3574..718a6c44f 100644
--- a/test/entt/core/type_traits.cpp
+++ b/test/entt/core/type_traits.cpp
@@ -101,6 +101,7 @@ TEST(TypeTraits, IsEqualityComparable) {
     static_assert(entt::is_equality_comparable_v<std::vector<std::vector<int>>>);
     static_assert(entt::is_equality_comparable_v<std::unordered_map<int, int>>);
     static_assert(entt::is_equality_comparable_v<std::unordered_map<int, std::unordered_map<int, char>>>);
+    static_assert(entt::is_equality_comparable_v<std::vector<not_comparable>::iterator>);
     static_assert(entt::is_equality_comparable_v<nlohmann_json_like>);
 
     static_assert(!entt::is_equality_comparable_v<not_comparable>);