std::weak_ptr::weak_ptr
De cppreference.com
<metanoindex/>
<tbody> </tbody> constexpr weak_ptr(); |
(1) | (desde C++11) |
weak_ptr( const weak_ptr& r ); |
(2) | (desde C++11) |
template< class Y > weak_ptr( const weak_ptr<Y>& r ); |
(2) | (desde C++11) |
template< class Y > weak_ptr( const std::shared_ptr<Y>& r ); |
(2) | (desde C++11) |
Constrói
weak_ptr novo que potencialmente partes de um objeto com r.Original:
Constructs new
weak_ptr that potentially shares an object with r.The text has been machine-translated via Google Translate.
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1)
Construtor padrão. Constrói
weak_ptr vazio.Original:
Default constructor. Constructs empty
weak_ptr.The text has been machine-translated via Google Translate.
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2)
Constrói
weak_ptr nova, que compartilha um objeto gerenciado pelo r. Se r gere nenhum objeto, *this gere nenhum objeto também. As sobrecargas templated não participar na resolução de sobrecarga, a menos Y* é implicitamente conversível para T*. Original:
Constructs new
weak_ptr which shares an object managed by r. If r manages no object, *this manages no object too. The templated overloads don't participate in the overload resolution unless Y* is implicitly convertible to T*. 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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Parâmetros
| r | - | um std::shared_ptr ou std::weak_ptr que será visto por este std::weak_ptr
Original: a std::shared_ptr or std::weak_ptr that will be viewed by this std::weak_ptr The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Exceções
Exemplo
#include <memory>
#include <iostream>
struct Foo {};
int main()
{
std::weak_ptr<Foo> w_ptr;
{
auto ptr = std::make_shared<Foo>();
w_ptr = ptr;
std::cout << "w_ptr.use_count() inside scope: " << w_ptr.use_count() << '\n';
}
std::cout << "w_ptr.use_count() out of scope: " << w_ptr.use_count() << '\n';
}
Saída:
w_ptr.use_count() inside scope: 1
w_ptr.use_count() out of scope: 0