diff options
| -rw-r--r-- | .vscode/c_cpp_properties.json | 4 | ||||
| -rw-r--r-- | include/newtype/impl/type_traits_extensions.hpp | 61 | ||||
| -rw-r--r-- | include/newtype/new_type.hpp | 18 | ||||
| -rw-r--r-- | test/src/arithmetic_suite.cpp | 37 |
4 files changed, 118 insertions, 2 deletions
diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json index 179e475..e71cdab 100644 --- a/.vscode/c_cpp_properties.json +++ b/.vscode/c_cpp_properties.json @@ -6,9 +6,9 @@ "${workspaceFolder}/**" ], "defines": [], - "compilerPath": "/usr/bin/clang", + "compilerPath": "/usr/bin/gcc", "cppStandard": "c++20", - "intelliSenseMode": "clang-x64", + "intelliSenseMode": "gcc-x64", "configurationProvider": "go2sh.cmake-integration" } ], diff --git a/include/newtype/impl/type_traits_extensions.hpp b/include/newtype/impl/type_traits_extensions.hpp index d6dbfd6..56824e2 100644 --- a/include/newtype/impl/type_traits_extensions.hpp +++ b/include/newtype/impl/type_traits_extensions.hpp @@ -577,6 +577,67 @@ namespace nt::impl template<typename T> auto constexpr is_nothrow_addable_v = is_nothrow_addable<T>::value; + /** + * @brief A trait to test if a given type is subtractable + * + * @tparam T The type to test + * @note This specialization forms the base case for non-subtractable T + */ + template<typename T, typename = void> + struct is_subtractable : std::false_type + { + }; + + /** + * @brief A trait to test if a given type is input streamable + * + * @tparam T The type to test + * @note This specialization forms the case for subtractable T + */ + template<typename T> + struct is_subtractable<T, std::void_t<decltype(std::declval<T const &>() + std::declval<T const &>())>> : std::true_type + { + }; + + /** + * @brief A variable template to test if a given type is subtractable + * + * @tparam T The type to test + */ + template<typename T> + auto constexpr is_subtractable_v = is_subtractable<T>::value; + + /** + * @brief A trait to test if a given type is noexcept subtractable + * + * @tparam T The type to test + * @note This specialization forms the base case for non-noexcept subtractable or non-subtractable T + */ + template<typename T, typename = void> + struct is_nothrow_subtractable : std::false_type + { + }; + + /** + * @brief A trait to test if a given type is noexcept subtractable + * + * @tparam T The type to test + * @note This specialization forms the case for subtractable T detemining if T is noexcept subtractable + */ + template<typename T> + struct is_nothrow_subtractable<T, std::void_t<decltype(std::declval<T const &>() + std::declval<T const &>())>> + : std::bool_constant<noexcept(std::declval<T const &>() + std::declval<T const &>())> + { + }; + + /** + * @brief A variable template to test if a given type is noexcept subtractable + * + * @tparam T The type to test + */ + template<typename T> + auto constexpr is_nothrow_subtractable_v = is_nothrow_subtractable<T>::value; + } // namespace arithmetic } // namespace nt::impl diff --git a/include/newtype/new_type.hpp b/include/newtype/new_type.hpp index 8228a94..bc8ecee 100644 --- a/include/newtype/new_type.hpp +++ b/include/newtype/new_type.hpp @@ -346,6 +346,24 @@ namespace nt return {lhs.decay() + rhs.decay()}; } + /** + * @brief Subtract two instances of the same nt::new_type + * + * @note This operator is only available if the derivation clause of the passed in nt::new_type objects contains nt::Arithmetic and the base + * type is subtractable. + * @param lhs The left-hand side of the subtraction + * @param rhs The right-hand side of the subtraction + * @return a new instance of the same nt::new_type + */ + template<typename BaseType, typename TagType, auto DerivationClause> + auto constexpr + operator-(new_type<BaseType, TagType, DerivationClause> const & lhs, new_type<BaseType, TagType, DerivationClause> const & rhs) noexcept( + impl::is_nothrow_subtractable_v<BaseType> && std::is_nothrow_copy_constructible_v<BaseType>) + -> std::enable_if_t<DerivationClause(nt::Arithmetic) && impl::is_subtractable_v<BaseType>, new_type<BaseType, TagType, DerivationClause>> + { + return {lhs.decay() - rhs.decay()}; + } + } // namespace nt #endif diff --git a/test/src/arithmetic_suite.cpp b/test/src/arithmetic_suite.cpp index 4541125..57c06e8 100644 --- a/test/src/arithmetic_suite.cpp +++ b/test/src/arithmetic_suite.cpp @@ -40,6 +40,37 @@ inline namespace addition_tests } // namespace addition_tests +inline namespace subtraction_tests +{ + + auto a_new__type_not_deriving_arithmetic_is_not_subtractable_with_instances_of_itself() -> void + { + using type_alias = nt::new_type<int, struct tag>; + ASSERT(!(nt::impl::is_subtractable_v<type_alias>)); + } + + auto a_new__type_deriving_arithmetic_is_subtractable_with_instances_of_itself() -> void + { + using type_alias = nt::new_type<int, struct tag, deriving(nt::Arithmetic)>; + ASSERT(nt::impl::is_subtractable_v<type_alias>); + } + + auto subtraction_of_two_instances_of_a_new__type_deriving_arithmetic_produces_an_instance_of_the_same_new__type() -> void + { + using type_alias = nt::new_type<int, struct tag, deriving(nt::Arithmetic)>; + ASSERT((std::is_same_v<type_alias, decltype(std::declval<type_alias const &>() + std::declval<type_alias const &>())>)); + } + + auto subtraction_of_two_instances_of_a_new__type_deriving_arithmetic_produces_the_correct_value_with_respect_to_the_base_type() -> void + { + using type_alias = nt::new_type<int, struct tag, deriving(nt::Arithmetic)>; + auto lhs = type_alias{24}; + auto rhs = type_alias{18}; + ASSERT_EQUAL(24 - 18, (lhs - rhs).decay()); + } + +} // namespace subtraction_tests + auto arithmetic_suite() -> std::pair<cute::suite, std::string> { return {{ @@ -48,6 +79,12 @@ auto arithmetic_suite() -> std::pair<cute::suite, std::string> KAWAII(a_new__type_deriving_arithmetic_is_addable_with_instances_of_itself), KAWAII(addition_of_two_instances_of_a_new__type_deriving_arithmetic_produces_an_instance_of_the_same_new__type), KAWAII(addition_of_two_instances_of_a_new__type_deriving_arithmetic_produces_the_correct_value_with_respect_to_the_base_type), + + /// Subtraction Tests + KAWAII(a_new__type_not_deriving_arithmetic_is_not_subtractable_with_instances_of_itself), + KAWAII(a_new__type_deriving_arithmetic_is_subtractable_with_instances_of_itself), + KAWAII(subtraction_of_two_instances_of_a_new__type_deriving_arithmetic_produces_an_instance_of_the_same_new__type), + KAWAII(subtraction_of_two_instances_of_a_new__type_deriving_arithmetic_produces_the_correct_value_with_respect_to_the_base_type), }, "Arithmetic Operators Tests"}; }
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