type info: removed has_type_index[_v] utility

src/entt/core/type_info.hpp

@@ -68,28 +68,6 @@ struct ENTT_API type_index {
 };
 
 
-/**
- * @brief Provides the member constant `value` to true if a given type is
- * indexable, false otherwise.
- * @tparam Type Potentially indexable type.
- */
-template<typename, typename = void>
-struct has_type_index: std::false_type {};
-
-
-/*! @brief has_type_index */
-template<typename Type>
-struct has_type_index<Type, std::void_t<decltype(type_index<Type>::value())>>: std::true_type {};
-
-
-/**
- * @brief Helper variable template.
- * @tparam Type Potentially indexable type.
- */
-template<typename Type>
-inline constexpr bool has_type_index_v = has_type_index<Type>::value;
-
-
 /**
  * @brief Type info.
  * @tparam Type Type for which to generate information.