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    std::weak_ptr::expired

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    weak_ptr::expired
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    <tbody> </tbody>
    bool expired() const;
    		 (seit C++11)

    Überprüft, ob das verwaltete Objekt bereits gelöscht wurde. Entspricht use_count() == 0 .

    Parameter

    (None)
    Original:
    (none)
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    Rückgabewert

    true wenn das verwaltete Objekt bereits gelöscht wurde, false sonst .

    Ausnahmen

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

    Notes

    expired() kann schneller sein als use_count() .
    Original:
    expired() may be faster than use_count().
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    Beispiel

    Veranschaulicht, wie abgelaufene verwendet wird, um die Gültigkeit des Zeigers überprüfen .
    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


    Siehe auch

    		 erzeugt einen shared_ptr, der das referenzierte Objekt verwaltet
    (öffentliche Elementfunktion) [edit]
    		gibt die Anzahl der shared_ptrs, die das selbe Objekte verwalten
    (öffentliche Elementfunktion) [edit]