Espacios de nombres
Variantes
Acciones

std::weak_ptr::expired

De cppreference.com
< cpp‎ | memory‎ | weak ptr

 
 
Utilidades de la biblioteca
Escriba apoyo (basic types, RTTI, type traits)
Gestión de memoria dinámica
Gestión de errores
Programa de servicios públicos
Funciones variadic
Fecha y hora
Objetos Function
initializer_list(C++11)
bitset
hash(C++11)
Operadores relacionales
Original:
Relational operators
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
Pares y tuplas
Original:
Pairs and tuples
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
pair
tuple(C++11)
piecewise_construct_t(C++11)
piecewise_construct(C++11)
Cambiar, hacia adelante y mover
Original:
Swap, forward and move
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
swap
forward(C++11)
move(C++11)
move_if_noexcept(C++11)
declval(C++11)
 
Gestión de memoria dinámica
Bajo la gestión de memoria de nivel
Los asignadores
Original:
Allocators
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
allocator
allocator_traits(C++11)
allocator_arg_t(C++11)
allocator_arg(C++11)
uses_allocator(C++11)
scoped_allocator_adaptor(C++11)
Inicializar el almacenamiento
Original:
Uninitialized storage
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
uninitialized_copy
uninitialized_copy_n(C++11)
uninitialized_fill
uninitialized_fill_n
raw_storage_iterator
get_temporary_buffer
return_temporary_buffer
Punteros inteligentes
Original:
Smart pointers
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
unique_ptr(C++11)
shared_ptr(C++11)
weak_ptr(C++11)
auto_ptr(obsoleto)
owner_less(C++11)
enable_shared_from_this(C++11)
bad_weak_ptr(C++11)
default_delete(C++11)
Garbage soporte colección
Original:
Garbage collection support
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
declare_reachable(C++11)
undeclare_reachable(C++11)
declare_no_pointers(C++11)
undeclare_no_pointers(C++11)
pointer_safety(C++11)
get_pointer_safety(C++11)
Varios
Original:
Miscellaneous
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
pointer_traits(C++11)
addressof(C++11)
align(C++11)
C Library
Original:
C Library
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
 
std::weak_ptr
Las funciones miembro
Original:
Member functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
weak_ptr::weak_ptr
weak_ptr::~weak_ptr
weak_ptr::operator=
Modificadores
Original:
Modifiers
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
weak_ptr::reset
weak_ptr::swap
Los observadores
Original:
Observers
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
weak_ptr::use_count
weak_ptr::expired
weak_ptr::lock
weak_ptr::owner_before
Terceros funciones
Original:
Non-member functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
std::swap
 
bool expired() const;
(desde C++11)
Comprueba si el objeto administrado ya se ha eliminado. Equivalente a use_count() == 0 .
Original:
Checks whether the managed object has already been deleted. Equivalent to use_count() == 0.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Contenido

[editar] Parámetros

(Ninguno)
Original:
(none)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[editar] Valor de retorno

true si el objeto administrado ya ha sido eliminado, por lo demás false .
Original:
true if the managed object has already been deleted, false otherwise.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[editar] Excepciones

noexcept specification:  
noexcept
  (desde C++11)

[editar] Notas

expired() puede ser más rápido que use_count() .
Original:
expired() may be faster than use_count().
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[editar] Ejemplo

Muestra cómo espirado se utiliza para comprobar la validez del puntero .
Original:
Demonstrates how expired is used to check validity of the pointer.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

#include <iostream>
#include <memory>
 
std::weak_ptr<int> gw;
 
void f()
{
    if (!gw.expired()) {
	std::cout << "gw is valid\n";
    }
    else {
        std::cout << "gw is expired\n";
    }
}
 
int main()
{
    {
        auto sp = std::make_shared<int>(42);
	gw = sp;
 
	f();
    }
 
    f();
}

Output:

gw is valid
gw is expired


[editar] Ver también

crea una shared_ptr que gestiona el objeto referenciado
Original:
creates a shared_ptr that manages the referenced object
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) [edit]
devuelve el número de objetos shared_ptr que gestionan el objeto
Original:
returns the number of shared_ptr objects that manage the object
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) [edit]