std::is_copy_constructible, std::is_trivially_copy_constructible, std::is_nothrow_copy_constructible
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| Defined in header <type_traits>
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| template< class T > struct is_copy_constructible; |
(1) | (ya que C + +11) |
| template< class T > struct is_trivially_copy_constructible; |
(2) | (ya que C + +11) |
| template< class T > struct is_nothrow_copy_constructible; |
(3) | (ya que C + +11) |
Comprueba si un tipo es
2) CopyConstructible, es decir, tiene un constructor copia accesible explícito o implícito. Si el requisito se cumple, un miembro constante value true igual se proporciona, de lo contrario es value false .Original:
Checks whether a type is
CopyConstructible, i.e. has an accessible explicit or implicit copy constructor. If the requirement is met, a member constant value equal true is provided, otherwise 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.
You can help to correct and verify the translation. Click here for instructions.
Igual que (1), pero la expresión constructor de copia no llama a ninguna operación que no es trivial .
3) Original:
Same as (1), but the copy constructor expression does not call any operation that is not trivial.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Igual que (1), pero la expresión constructor de copia se noexcept .
Original:
Same as (1), but the copy constructor expression is noexcept.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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Contenido |
Inherited from std::integral_constant
Member constants
| value [estático] |
true si T is copy-constructible , false lo contrario Original: true if T is copy-constructible , false otherwise The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (público miembro constante estática) |
Member functions
| operator bool |
convierte el objeto a bool, devuelve 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. (miembro público función) |
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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bool
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type
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std::integral_constant<bool, value> |
[editar] Posible implementación
template<class T> struct is_copy_constructible : std::is_constructible<T, const typename std::add_lvalue_reference<T>::type> {}; template<class T> struct is_trivially_copy_constructible : std::is_trivially_constructible<T, const typename std::add_lvalue_reference<T>::type> {}; template<class T> struct is_nothrow_copy_constructible : std::is_nothrow_constructible<T, const typename std::add_lvalue_reference<T>::type> {}; |
[editar] Ejemplo
#include <iostream> #include <type_traits> struct Ex1 { std::string str; // member has a non-trivial copy ctor }; struct Ex2 { int n; Ex2(const Ex2&) = default; // trivial and non-throwing }; int main() { std::cout << std::boolalpha << "Ex1 is copy-constructible? " << std::is_copy_constructible<Ex1>::value << '\n' << "Ex1 is trivially copy-constructible? " << std::is_trivially_copy_constructible<Ex1>::value << '\n' << "Ex2 is trivially copy-constructible? " << std::is_trivially_copy_constructible<Ex2>::value << '\n' << "Ex2 is nothrow copy-constructible? " << std::is_nothrow_copy_constructible<Ex2>::value << '\n'; }
Output:
Ex1 is copy-constructible? true Ex1 is trivially copy-constructible? false Ex2 is trivially copy-constructible? true Ex2 is nothrow copy-constructible? true
[editar] Ver también
| (C++11) (C++11) (C++11) |
Comprueba si un tipo tiene un constructor de argumentos concretos Original: checks if a type has a constructor for specific arguments The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (clase de plantilla) |
| Comprueba si un tipo tiene un constructor por defecto Original: checks if a type has a default constructor The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (clase de plantilla) | |
| (C++11) (C++11) (C++11) |
Comprueba si un tipo tiene un constructor movimiento Original: checks if a type has a move constructor The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (clase de plantilla) |