std::extent
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| Defined in header <type_traits>
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| template< class T, unsigned N = 0> struct extent; |
(a partir do C++ 11) | |
If T is an array type, provides the member constant value equal to the number of elements along the Nth dimension of the array, if N is in [0, std::rank<T>::value). For any other type, or if T is array of unknown bound along its first dimension and N is 0, value is 0.
Índice |
Inherited from std::integral_constant
Member constants
| value [estática] |
the number of elements along the Nth dimension of T (membro estático público constante) |
Member functions
| operator std::size_t |
converte o objeto em std::size_t, retorna value Original: converts the object to std::size_t, returns value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) |
Member types
| Tipo
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
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std::size_t
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type
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std::integral_constant<std::size_t, value> |
[editar] Possível implementação
template<class T, unsigned N = 0> struct extent : std::integral_constant<std::size_t, 0> {}; template<class T> struct extent<T[], 0> : std::integral_constant<std::size_t, 0> {}; template<class T, unsigned N> struct extent<T[], N> : std::integral_constant<std::size_t, std::extent<T, N-1>::value> {}; template<class T, std::size_t N> struct extent<T[N], 0> : std::integral_constant<std::size_t, N> {}; template<class T, std::size_t I, unsigned N> struct extent<T[I], N> : std::integral_constant<std::size_t, std::extent<T, N-1>::value> {}; |
[editar] Exemplo
#include <iostream> #include <type_traits> int main() { std::cout << std::extent<int[3]>::value << '\n'; std::cout << std::extent<int[3][4]>::value << '\n'; std::cout << std::extent<int[3][4],1>::value << '\n'; std::cout << std::extent<int[3][4],2>::value << '\n'; std::cout << std::extent<int[]>::value << '\n'; }
Output:
3 3 4 0 0
[editar] Veja também
| (C++11) |
verifica se o tipo é um tipo de matriz Original: checks if a type is an array type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) |
| (C++11) |
obtém o número de dimensões de um tipo de matriz Original: obtains the number of dimensions of an array type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) |
| (C++11) |
remove uma medida do tipo matriz dada Original: removes one extent from the given array type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de classe) |
| (C++11) |
removes all extents from the given array type (modelo de classe) |
