std::enable_shared_from_this<T>::shared_from_this

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

#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

std::enable_shared_from_this<T>::shared_from_this

Return value

Exceptions

Example

See also