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std::shared_ptr::operator=(3) C++ Standard Libary std::shared_ptr::operator=(3)

NAME

std::shared_ptr::operator= - std::shared_ptr::operator=

Synopsis


shared_ptr& operator=( const shared_ptr& r ) noexcept; (1)
template< class Y > (2)
shared_ptr& operator=( const shared_ptr<Y>& r ) noexcept;
shared_ptr& operator=( shared_ptr&& r ) noexcept; (3)
template< class Y > (4)
shared_ptr& operator=( shared_ptr<Y>&& r ) noexcept;
template< class Y > (5) (deprecated in C++11)
shared_ptr& operator=( std::auto_ptr<Y>&& r ); (removed in C++17)
template< class Y, class Deleter > (6)
shared_ptr& operator=( std::unique_ptr<Y, Deleter>&& r );


Replaces the managed object with the one managed by r.


If *this already owns an object and it is the last shared_ptr owning it, and r is
not the same as *this, the object is destroyed through the owned deleter.


1,2) Shares ownership of the object managed by r. If r manages no object, *this
manages no object too. Equivalent to shared_ptr<T>(r).swap(*this).
3,4) Move-assigns a shared_ptr from r. After the assignment, *this contains a copy
of the previous state of r, and r is empty. Equivalent to
shared_ptr<T>(std::move(r)).swap(*this).
5) Transfers the ownership of the object managed by r to *this. If r manages no
object, *this manages no object too. After the assignment, *this contains the
pointer previously held by r, and use_count() == 1; also r is empty. Equivalent to
shared_ptr<T>(r).swap(*this).
6) Transfers the ownership of the object managed by r to *this. The deleter
associated to r is stored for future deletion of the managed object. r manages no
object after the call. Equivalent to shared_ptr<T>(std::move(r)).swap(*this).

Parameters


r - another smart pointer to share the ownership to or acquire the ownership from

Return value


*this

Notes


The implementation may meet the requirements without creating a temporary shared_ptr
object.

Exceptions


5,6) May throw implementation-defined exceptions.

Example


This section is incomplete
Reason: no example

See also


reset replaces the managed object
(public member function)

Category:


* Todo no example

2024.06.10 http://cppreference.com