boost::openmethod::weak_virtual_ptr::lock

Lock the weak pointer

Synopsis

Declared in <boost/openmethod/interop/std_weak_ptr.hpp>

virtual_ptr<std::shared_ptr<Class>, Registry>
lock() const;

Description

Return a shared_virtual_ptr to the object, using the remembered v‐table pointer. No hash table lookup is performed.

Example

struct Animal {
    virtual ~Animal() = default;
};
struct Dog : Animal {};
struct Cat : Animal {};

BOOST_OPENMETHOD_CLASSES(Animal, Dog, Cat);

shared_virtual_ptr<Animal> animal = make_shared_virtual<Dog>();
weak_virtual_ptr<Animal> observer = animal;

std::cout << poke(observer.lock()) << "\n"; // bark

animal = nullptr;
std::cout << std::boolalpha << observer.expired() << "\n"; // true

Return Value

A shared_virtual_ptr to the object if it still exists, or an empty shared_virtual_ptr with a nullptr v‐table pointer otherwise.

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