Varianti

    std::weak_ptr::expired

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    <tbody> </tbody>
    bool expired() const;
    		 (dal C++11)
    Controlla se l'oggetto gestito è già stato cancellato. Equivalente a use_count() == 0.
    Original:
    Checks whether the managed object has already been deleted. Equivalent to use_count() == 0.
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    Parametri

    (Nessuno)
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    (none)
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    Valore di ritorno

    true se l'oggetto gestito è già stato eliminato, false altrimenti.
    Original:
    true if the managed object has already been deleted, false otherwise.
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    Eccezioni

    noexcept specification:  
    <tbody> </tbody>
    noexcept
      (dal C++11)

    Note

    expired() può essere più veloce use_count().
    Original:
    expired() may be faster than use_count().
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    Esempio

    Viene illustrato come scaduto viene utilizzato per controllare la validità del puntatore .
    Original:
    Demonstrates how expired is used to check validity of the pointer.
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    #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


    Vedi anche
    crea un shared_ptr che gestisce l'oggetto indicato
    Original:
    creates a shared_ptr that manages the referenced object
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    (metodo pubblico) [modifica]
    restituisce il numero di oggetti shared_ptr che gestiscono l'oggetto
    Original:
    returns the number of shared_ptr objects that manage the object
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    (metodo pubblico) [modifica]