Namespaces
Variants
Views
Actions

std::enable_shared_from_this::shared_from_this

From cppreference.com
 
 
 
 
 
shared_ptr<T> shared_from_this();
(1)
shared_ptr<T const> shared_from_this() const;
(2)

Returns a std::shared_ptr<T> that shares ownership of *this with all existing std::shared_ptr<T> that refer to *this.

Contents

Notes

Before calling shared_from_this, there should be at least one std::shared_ptr<T> p that owns *this.

Return value

std::shared_ptr<T> that shares ownership of *this with pre-existing std::shared_ptr<T>s

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

See also

smart pointer with shared object ownership semantics
(class template) [edit]