Пространства имён
Варианты
Действия

std::decay

Материал из cppreference.com

 
 
 
Поддержка типов
Основные типы
Original:
Basic types
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Основные типы
Исправлены типы целых ширину (C++11)
Числовые пределы
Original:
Numeric limits
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numeric_limits
С числовым ограничивает интерфейс
Время тип информации
Original:
Runtime type information
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Тип черты
Original:
Type traits
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Первичные категории типа
Original:
Primary type categories
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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
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is_const(C++11)
is_volatile(C++11)
is_pod(C++11)
is_empty(C++11)
is_polymorphic(C++11)
is_abstract(C++11)
Поддерживаемые операции
Original:
Supported operations
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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
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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
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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)
Тип преобразования
Original:
Type transformations
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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
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integral_constant(C++11)
 
Заголовочный файл <type_traits>
template< class T >
struct decay;
(начиная с C++11)
Применяется именующее к RValue, массива в указатель, и функция в указатель неявное преобразование к типу T, снимает CV-классификаторов, а также определяет тип результате как член ЬурейеЕ type. Это преобразование типа применяется ко всем аргументам функции, когда передаются по значению.
Original:
Applies lvalue-to-rvalue, array-to-pointer, and function-to-pointer implicit conversions to the type T, removes cv-qualifiers, and defines the resulting type as the member typedef type. This is the type conversion applied to all function arguments when passed by value.
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Содержание

[править] Член типов

Имя
Original:
Name
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Definition
type
Результат применения преобразования распада типа T
Original:
the result of applying the decay type conversions to T
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[править] Возможная реализация

template< class T >
struct decay {
    typedef typename std::remove_reference<T>::type U;
    typedef typename std::conditional<
        std::is_array<U>::value,
        typename std::remove_extent<U>::type*,
        typename std::conditional<
            std::is_function<U>::value,
            typename std::add_pointer<U>::type,
            typename std::remove_cv<U>::type
        >::type
    >::type type;
};

[править] Пример

[править] См. также

implicit conversion
массива в указатель, функции в указатель, RValue к именующее преобразований
Original:
array-to-pointer, function-to-pointer, rvalue-to-lvalue conversions
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