std::enable_shared_from_this<T>::shared_from_this
From cppreference.com
std::shared_ptr<T> shared_from_this();
|
(1) | (since C++11) (constexpr since C++26) |
std::shared_ptr<const T> shared_from_this() const;
|
(2) | (since C++11) (constexpr since C++26) |
Returns a std::shared_ptr that shares ownership of *this with all existing std::shared_ptr that refer to *this.
Return value
std::shared_ptr<T>(weak_this )
Exceptions
If shared_from_this is called on an object that is not previously shared by std::shared_ptr, std::bad_weak_ptr is thrown by the std::shared_ptr constructor.
Example
Run this code
#include <iostream>
#include <memory>
struct Foo : public std::enable_shared_from_this<Foo>
{
Foo() { std::cout << "Foo::Foo\n"; }
~Foo() { std::cout << "Foo::~Foo\n"; }
std::shared_ptr<Foo> getFoo() { return shared_from_this(); }
};
int main()
{
Foo *f = new Foo;
std::shared_ptr<Foo> pf1;
{
std::shared_ptr<Foo> pf2(f);
pf1 = pf2->getFoo(); // shares ownership of object with pf2
}
std::cout << "pf2 is gone\n";
}
Output:
Foo::Foo
pf2 is gone
Foo::~Foo
See also
(C++11) |
smart pointer with shared object ownership semantics (class template) |