is used SHOW( std::is_same<int, std::int64_t>::value ); // maybe false // same tests as above, except using C++17's std::is_same_v<T, U> format SHOW( std::is_same_v<int, std::int32_t> ); // maybe true SHOW( std:
is_same (C++11) is_base_of (C++11) is_virtual_base_of (C++26) is_convertibleis_nothrow_convertible (C++11)(C++20) is_layout_compatible (C++20) is_pointer_interconvertible_base_of (C++20) is_pointer_interconvertible_with_class (C++20) is_corresponding_member (C++20) alignment_of (C++...
template<classT>structis_null_pointer:std::is_same<std::nullptr_t,std::remove_cv_t<T>>{}; 注解 对于std::nullptr_t,std::is_pointer是false,因为它不是内建指针类型。 在libc++ 中,std::is_null_pointer不能在 C++11 模式中使用。
U> concept either = (std::same_as<T, U> || ...); template<typename T> concept is_printable = std::integral<T> || std::floating_point<T> || either<std::remove_cvref_t<std::remove_pointer_t<std::decay_t<T>>>, char, wchar_t>; void println(is_printable auto const ... ...
template<classT>structis_floating_point:std::integral_constant<bool,std::is_same<float,typenamestd::remove_cv<T>::type>::value||std::is_same<double,typenamestd::remove_cv<T>::type>::value||std::is_same<longdouble,typenamestd::remove_cv<T>::type>::value>{}; ...
template<class T> struct is_floating_point : std::integral_constant< bool, // 注:标准浮点数类型 std::is_same<float, typename std::remove_cv<T>::type>::value || std::is_same<double, typename std::remove_cv<T>::type>::value || std::is_same<long double, typename std::remove_...
is_same (C++11) is_base_of (C++11) is_virtual_base_of (C++26) is_convertibleis_nothrow_convertible (C++11)(C++20) is_layout_compatible (C++20) is_pointer_interconvertible_base_of (C++20) is_pointer_interconvertible_with_class (C++20) is_corresponding_member (C++20) alignment_of (C++...
template<class T> struct is_void : std::is_same<void, typename std::remove_cv<T>::type> {}; Example Run this code #include <type_traits> void foo(); static_assert ( std::is_void_v<void> == true and std::is_void_v<const void> == true and std::is_void_v<volatile void>...
Ifstd::is_same<C, Obj>::value||std::is_base_of<C, Obj>::valueistrue (obj.*f)(arg_1, arg_2, ..., arg_N)(invoke the member function on the object). IfObjis a specialization ofstd::reference_wrapper (obj.get().*f)(arg_1, arg_2, ..., arg_N)(invoke the member functi...
template<class T> struct is_void : std::is_same<void, typename std::remove_cv<T>::type> {}; Example Run this code #include <type_traits> void foo(); static_assert ( std::is_void_v<void> == true and std::is_void_v<const void> == true and std::is_void_v<volatile void>...