std::enable_shared_from_this<T>:: shared_from_this

Returns a std:: shared_ptr < T > 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

#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";   
}

Foo::Foo
pf2 is gone
Foo::~Foo

See also