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      std::weak_ptr::expired

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      rel_ops::operator!=
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      std::weak_ptr
      Funções de membro
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      weak_ptr::use_count
      weak_ptr::expired
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      weak_ptr::owner_before
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      <tbody> </tbody>
      bool expired() const;
      		 (desde C++11)
      Verifica se o objeto gerenciado já foi excluído. Equivalente a use_count() == 0.
      Original:
      Checks whether the managed object has already been deleted. Equivalent to use_count() == 0.
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      Parâmetros

      (Nenhum)
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      (none)
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      Valor de retorno

      true se o objeto gerenciado já foi excluído, false outra forma.
      Original:
      true if the managed object has already been deleted, false otherwise.
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      Exceções

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

      Notas

      expired() pode ser mais rápida do que use_count().
      Original:
      expired() may be faster than use_count().
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      Exemplo

      Demonstra como expirado é utilizado para verificar a validade do ponteiro .
      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();
}

      Saída: 

      gw is valid
gw is expired


      Veja também
      cria um shared_ptr que gerencia o objeto referenciado
      Original:
      creates a shared_ptr that manages the referenced object
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      (função pública membro) [edit]
      retorna o número de objetos shared_ptr que gerenciam o objeto
      Original:
      returns the number of shared_ptr objects that manage the object
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      (função pública membro) [edit]