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

type_traits: type_list_transform[_t] utility

Browse Source
This commit is contained in:
Michele Caini
2022-05-24 10:59:40 +02:00
parent a85ad88d5a
commit 48ab892de1
2 changed files with 31 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

@@ -329,6 +329,28 @@ struct type_list_diff<type_list<Type...>, type_list<Other...>> {
template<typename... List>
using type_list_diff_t = typename type_list_diff<List...>::type;
/*! @brief Primary template isn't defined on purpose. */
template<typename, template<typename...> class>
struct type_list_transform;
/**
* @brief Computes the difference between two type lists.
* @tparam Type Types provided by the type list.
* @tparam Op Unary operation as template class with a type member named `type`.
*/
template<typename... Type, template<typename...> class Op>
struct type_list_transform<type_list<Type...>, Op> {
using type = type_list<typename Op<Type>::type...>;
};
/**
* @brief Helper type.
* @tparam List Type list.
* @tparam Op Unary operation as template class with a type member named `type`.
*/
template<typename List, template<typename...> class Op>
using type_list_transform_t = typename type_list_transform<List, Op>::type;
/**
* @brief A class to use to push around lists of constant values, nothing more.
* @tparam Value Values provided by the value list.

9
test/entt/core/type_traits.cpp
View File

@@ -34,6 +34,11 @@ struct clazz {
void free_function(int, const double &) {}
template<typename, typename Type = void>
struct multi_argument_operation {
using type = Type;
};
TEST(SizeOf, Functionalities) {
static_assert(entt::size_of_v<void> == 0u);
static_assert(entt::size_of_v<char> == sizeof(char));
@@ -101,6 +106,10 @@ TEST(TypeList, Functionalities) {
static_assert(std::is_same_v<entt::type_list_diff_t<entt::type_list<int, char, double>, entt::type_list<int, char>>, entt::type_list<double>>);
static_assert(std::is_same_v<entt::type_list_diff_t<entt::type_list<int, char, double>, entt::type_list<char, double>>, entt::type_list<int>>);
static_assert(std::is_same_v<entt::type_list_diff_t<entt::type_list<int, char, double>, entt::type_list<char>>, entt::type_list<int, double>>);
static_assert(std::is_same_v<entt::type_list_transform_t<entt::type_list<int, char>, entt::type_identity>, entt::type_list<int, char>>);
static_assert(std::is_same_v<entt::type_list_transform_t<entt::type_list<int, char>, std::add_const>, entt::type_list<const int, const char>>);
static_assert(std::is_same_v<entt::type_list_transform_t<entt::type_list<int, char>, multi_argument_operation>, entt::type_list<void, void>>);
}
TEST(ValueList, Functionalities) {