entity: adds to_entity and to_version to the entt namespace (see #788)

src/entt/entity/entity.hpp

@@ -130,14 +130,30 @@ public:
 };
 
 /**
- * @brief Converts an entity to its underlying type.
+ * @copydoc entt_traits<Entity>::to_integral
  * @tparam Entity The value type.
- * @param entity The value to convert.
- * @return The integral representation of the given value.
  */
 template<typename Entity>
-[[nodiscard]] constexpr typename entt_traits<Entity>::entity_type to_integral(const Entity entity) ENTT_NOEXCEPT {
-    return entt_traits<Entity>::to_integral(entity);
+[[nodiscard]] constexpr typename entt_traits<Entity>::entity_type to_integral(const Entity value) ENTT_NOEXCEPT {
+    return entt_traits<Entity>::to_integral(value);
+}
+
+/**
+ * @copydoc entt_traits<Entity>::to_entity
+ * @tparam Entity The value type.
+ */
+template<typename Entity>
+[[nodiscard]] constexpr typename entt_traits<Entity>::entity_type to_entity(const Entity value) ENTT_NOEXCEPT {
+    return entt_traits<Entity>::to_entity(value);
+}
+
+/**
+ * @copydoc entt_traits<Entity>::to_version
+ * @tparam Entity The value type.
+ */
+template<typename Entity>
+[[nodiscard]] constexpr typename entt_traits<Entity>::version_type to_version(const Entity value) ENTT_NOEXCEPT {
+    return entt_traits<Entity>::to_version(value);
 }
 
 /*! @brief Null object for all identifiers.  */

test/entt/entity/entity.cpp

@@ -14,20 +14,20 @@ TEST(Entity, Traits) {
     const auto entity = registry.create();
     const auto other = registry.create();
 
-    ASSERT_EQ(entt::to_integral(entity), traits_type::to_integral(entity));
+    ASSERT_EQ(entt::to_integral(entity), entt::to_integral(entity));
     ASSERT_NE(entt::to_integral(entity), entt::to_integral<entt::entity>(entt::null));
     ASSERT_NE(entt::to_integral(entity), entt::to_integral(entt::entity{}));
 
-    ASSERT_EQ(traits_type::to_entity(entity), 0u);
-    ASSERT_EQ(traits_type::to_version(entity), 1u);
-    ASSERT_EQ(traits_type::to_entity(other), 1u);
-    ASSERT_EQ(traits_type::to_version(other), 0u);
+    ASSERT_EQ(entt::to_entity(entity), 0u);
+    ASSERT_EQ(entt::to_version(entity), 1u);
+    ASSERT_EQ(entt::to_entity(other), 1u);
+    ASSERT_EQ(entt::to_version(other), 0u);
 
-    ASSERT_EQ(traits_type::construct(traits_type::to_entity(entity), traits_type::to_version(entity)), entity);
-    ASSERT_EQ(traits_type::construct(traits_type::to_entity(other), traits_type::to_version(other)), other);
-    ASSERT_NE(traits_type::construct(traits_type::to_entity(entity), {}), entity);
+    ASSERT_EQ(traits_type::construct(entt::to_entity(entity), entt::to_version(entity)), entity);
+    ASSERT_EQ(traits_type::construct(entt::to_entity(other), entt::to_version(other)), other);
+    ASSERT_NE(traits_type::construct(entt::to_entity(entity), {}), entity);
 
-    ASSERT_EQ(traits_type::construct(traits_type::to_entity(other), traits_type::to_version(entity)), traits_type::combine(traits_type::to_integral(other), traits_type::to_integral(entity)));
+    ASSERT_EQ(traits_type::construct(entt::to_entity(other), entt::to_version(entity)), traits_type::combine(entt::to_integral(other), entt::to_integral(entity)));
 
     ASSERT_EQ(traits_type::combine(entt::tombstone, entt::null), tombstone);
     ASSERT_EQ(traits_type::combine(entt::null, entt::tombstone), null);
@@ -44,8 +44,8 @@ TEST(Entity, Null) {
     entt::registry registry{};
     const auto entity = registry.create();
 
-    ASSERT_EQ(traits_type::combine(entt::null, traits_type::to_integral(entity)), (traits_type::construct(traits_type::to_entity(null), traits_type::to_version(entity))));
-    ASSERT_EQ(traits_type::combine(entt::null, traits_type::to_integral(null)), null);
+    ASSERT_EQ(traits_type::combine(entt::null, entt::to_integral(entity)), (traits_type::construct(entt::to_entity(null), entt::to_version(entity))));
+    ASSERT_EQ(traits_type::combine(entt::null, entt::to_integral(null)), null);
     ASSERT_EQ(traits_type::combine(entt::null, entt::tombstone), null);
 
     registry.emplace<int>(entity, 42);
@@ -73,8 +73,8 @@ TEST(Entity, Tombstone) {
     entt::registry registry{};
     const auto entity = registry.create();
 
-    ASSERT_EQ(traits_type::combine(traits_type::to_integral(entity), entt::tombstone), (traits_type::construct(traits_type::to_entity(entity), traits_type::to_version(tombstone))));
-    ASSERT_EQ(traits_type::combine(entt::tombstone, traits_type::to_integral(tombstone)), tombstone);
+    ASSERT_EQ(traits_type::combine(entt::to_integral(entity), entt::tombstone), (traits_type::construct(entt::to_entity(entity), entt::to_version(tombstone))));
+    ASSERT_EQ(traits_type::combine(entt::tombstone, entt::to_integral(tombstone)), tombstone);
     ASSERT_EQ(traits_type::combine(entt::tombstone, entt::null), tombstone);
 
     registry.emplace<int>(entity, 42);
@@ -85,8 +85,8 @@ TEST(Entity, Tombstone) {
     ASSERT_TRUE(entity != entt::tombstone);
     ASSERT_TRUE(entt::tombstone != entity);
 
-    const auto vers = traits_type::to_version(entt::tombstone);
-    const auto other = traits_type::construct(traits_type::to_entity(entity), vers);
+    constexpr auto vers = entt::to_version(tombstone);
+    const auto other = traits_type::construct(entt::to_entity(entity), vers);
 
     ASSERT_FALSE(registry.valid(entt::tombstone));
     ASSERT_NE(registry.destroy(entity, vers), vers);