std::is_class

 

C++

Язык

Понятия (концепции)

Утилиты

Строки

Контейнеры

Алгоритмы

Итераторы

Работа с числами

Ввод / вывод

Локализация

Регулярные выражения (C++11)

Атомарные примитивы (C++11)

Потоки (C++11)

 

Утилиты библиотеки

Поддежка типов (базовые типы, RTTI, type traits)

Динамическое управление памятью

Обработка ошибок

Управление жизненным циклом программы

Функции с переменным числом аргументов

Дата и время

Функциональные объекты

initializer_list (C++11)

bitset

hash (C++11)

Реляционные операторы

rel_ops::operator!= rel_ops::operator> rel_ops::operator<= rel_ops::operator>=

Пары и кортежи

pair

tuple (C++11)

piecewise_construct_t (C++11)

piecewise_construct (C++11)

Обмен, передача и перемещение

swap

forward (C++11)

move (C++11)

move_if_noexcept (C++11)

declval (C++11)

 

Поддержка типов

Основные типы Original: Basic types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Основные типы
Исправлены типы целых ширину (C++11)
ptrdiff_t size_t max_align_t (C++11)	nullptr_t (C++11) offsetof NULL
Числовые пределы Original: Numeric limits The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
numeric_limits
С числовым ограничивает интерфейс
Время тип информации Original: Runtime type information The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
type_info type_index (C++11)	bad_typeid bad_cast
Тип черты Original: Type traits The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Первичные категории типа Original: Primary type categories The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_void (C++11) is_array (C++11) is_pointer (C++11) is_enum (C++11) is_union (C++11) is_class (C++11) is_function (C++11)	is_object (C++11) is_scalar (C++11) is_compound (C++11) is_integral (C++11) is_floating_point (C++11) is_fundamental (C++11) is_arithmetic (C++11)
is_reference (C++11)
is_lvalue_reference (C++11)
is_rvalue_reference (C++11)
is_member_pointer (C++11)
is_member_object_pointer (C++11)
is_member_function_pointer (C++11)

Тип свойства Original: Type properties The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_const (C++11) is_volatile (C++11) is_pod (C++11) is_empty (C++11) is_polymorphic (C++11) is_abstract (C++11)	is_trivial (C++11) is_trivially_copyable (C++11) is_standard_layout (C++11) is_literal_type (C++11) is_signed (C++11) is_unsigned (C++11)

Поддерживаемые операции Original: Supported operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_constructible is_trivially_constructible is_nothrow_constructible (C++11) (C++11) (C++11)
is_default_constructible is_trivially_default_constructible is_nothrow_default_constructible (C++11) (C++11) (C++11)
is_copy_constructible is_trivially_copy_constructible is_nothrow_copy_constructible (C++11) (C++11) (C++11)
is_move_constructible is_trivially_move_constructible is_nothrow_move_constructible (C++11) (C++11) (C++11)
is_assignable is_trivially_assignable is_nothrow_assignable (C++11) (C++11) (C++11)
is_copy_assignable is_trivially_copy_assignable is_nothrow_copy_assignable (C++11) (C++11) (C++11)
is_move_assignable is_trivially_move_assignable is_nothrow_move_assignable (C++11) (C++11) (C++11)
is_destructible is_trivially_destructible is_nothrow_destructible (C++11) (C++11) (C++11)
has_virtual_destructor (C++11)
Отношения собственности и запросов Original: Relationships and property queries The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
is_same (C++11) is_base_of (C++11) is_convertible (C++11)	alignment_of (C++11) rank (C++11) extent (C++11)
Тип модификаций Original: Type modifications The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
remove_cv remove_const remove_volatile (C++11) (C++11) (C++11) add_cv add_const add_volatile (C++11) (C++11) (C++11) make_signed (C++11) make_unsigned (C++11)	remove_reference (C++11) add_lvalue_reference add_rvalue_reference (C++11) (C++11) remove_pointer (C++11) add_pointer (C++11) remove_extent (C++11) remove_all_extents (C++11)
Тип преобразования Original: Type transformations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
aligned_storage (C++11) aligned_union (C++11) decay (C++11) enable_if (C++11)	conditional (C++11) common_type (C++11) underlying_type (C++11) result_of (C++11)
Введите черта констант Original: Type trait constants The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
integral_constant (C++11)

 

Заголовочный файл <type_traits>
template< class T > struct is_class;		(начиная с C++11)

Если T является классе или структуре (но не союз), обеспечивает постоянный член value равных true. Для любого другого типа, value является false.

Original:

If T is a class or struct (but not a union), provides the member constant value equal true. For any other type, value is false.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Унаследован от std::integral_constant

Member constants

value [static]	true если T is a class or struct , false иначе Original: true if T is a class or struct , false otherwise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (public static константа-член)

Member functions

operator bool	преобразует объект в bool, возвращает value Original: converts the object to bool, returns value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (public функция-член)

Member types

Type Original: Type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition
value_type	bool
type	std::integral_constant<bool, value>

Пример

#include <iostream>
#include <type_traits>
 
struct A {};
 
class B {};
 
enum class C {};
 
int main()
{
    std::cout << std::boolalpha;
    std::cout << std::is_class<A>::value << '\n';
    std::cout << std::is_class<B>::value << '\n';
    std::cout << std::is_class<C>::value << '\n';
    std::cout << std::is_class<int>::value << '\n';
}

Вывод:

true
true
false
false

См. также

is_union (C++11)	проверяет, является ли тип объединения типа Original: checks if a type is an union type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (шаблон класса)