Scarfski/entt
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

type_traits: value_list_diff[_t]

Browse Source
This commit is contained in:
Michele Caini
2023-03-26 12:46:27 +02:00
parent b272e04bab
commit 9ce07ff617
2 changed files with 28 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
src/entt/core/type_traits.hpp
View File

@@ -558,6 +558,28 @@ struct value_list_contains<value_list<Value...>, Other>
template<typename List, auto Value>
inline constexpr bool value_list_contains_v = value_list_contains<List, Value>::value;
/*! @brief Primary template isn't defined on purpose. */
template<typename...>
struct value_list_diff;
/**
* @brief Computes the difference between two value lists.
* @tparam Value Values provided by the first value list.
* @tparam Other Values provided by the second value list.
*/
template<auto... Value, auto... Other>
struct value_list_diff<value_list<Value...>, value_list<Other...>> {
/*! @brief A value list that is the difference between the two value lists. */
using type = value_list_cat_t<std::conditional_t<value_list_contains_v<value_list<Other...>, Value>, value_list<>, value_list<Value>>...>;
};
/**
* @brief Helper type.
* @tparam List Value lists between which to compute the difference.
*/
template<typename... List>
using value_list_diff_t = typename value_list_diff<List...>::type;
/*! @brief Same as std::is_invocable, but with tuples. */
template<typename, typename>
struct is_applicable: std::false_type {};

6
test/entt/core/type_traits.cpp
View File

@@ -138,6 +138,12 @@ TEST(ValueList, Functionalities) {
static_assert(entt::value_list_index_v<0, value> == 0u);
static_assert(entt::value_list_index_v<2, value> == 1u);
static_assert(entt::value_list_index_v<1, other> == 0u);
static_assert(std::is_same_v<entt::value_list_diff_t<entt::value_list<0, 1, 2>, entt::value_list<3, 4>>, entt::value_list<0, 1, 2>>);
static_assert(std::is_same_v<entt::value_list_diff_t<entt::value_list<0, 1, 2>, entt::value_list<0, 1, 2>>, entt::value_list<>>);
static_assert(std::is_same_v<entt::value_list_diff_t<entt::value_list<0, 1, 2>, entt::value_list<0, 1>>, entt::value_list<2>>);
static_assert(std::is_same_v<entt::value_list_diff_t<entt::value_list<0, 1, 2>, entt::value_list<1, 2>>, entt::value_list<0>>);
static_assert(std::is_same_v<entt::value_list_diff_t<entt::value_list<0, 1, 2>, entt::value_list<1>>, entt::value_list<0, 2>>);
}
TEST(IsApplicable, Functionalities) {