std::enable_shared_from_this::operator= (3) Linux Manual Page

std::enable_shared_from_this<T>::operator= – std::enable_shared_from_this<T>::operator=

Synopsis

enable_shared_from_this<T> &operator=(const enable_shared_from_this<T> &obj) noexcept;
(since C++ 11)

Does nothing; returns *this.

Parameters

obj – an enable_shared_from_this to assign to *this

Return value

*this

Notes

The private std::weak_ptr<T> member is not affected by this assignment operator.

Example

Note: enable_shared_from_this::operator= is defined as protected in order to prevent accidental slicing but allow derived classes to have default assignment operators.
// Run this code

#include <memory>

#include <iostream>
class SharedInt : public std::enable_shared_from_this<SharedInt>

{

  public:
    explicit SharedInt(int n)
        : mNumber(n)
    {
    }
    SharedInt(const SharedInt &) = default;
    SharedInt(SharedInt &&) = default;
    ~SharedInt() = default;
    // Both assignment operators use enable_shared_from_this::operator=
    SharedInt &operator=(const SharedInt &) = default;
    SharedInt &operator=(SharedInt &&) = default;
    int number() const
    {
        return mNumber;
    }

  private:
    int mNumber;
};
int main()
{
    std::shared_ptr<SharedInt> a = std::make_shared<SharedInt>(2);
    std::shared_ptr<SharedInt> b = std::make_shared<SharedInt>(4);
    *a = *b;
    std::cout << a->number() << std::endl;
}

Output:

  4

See also

shared_ptr smart pointer with shared object ownership semantics
           (class template)
(C++11)