std::shared_ptr::unique

`bool unique() const noexcept;`		( C++17) ( C++20)

, *this shared_ptr, , .. use_count() == 1.

()

true, *this shared_ptr, , false .

C++17 C++20, use_count ( use_count).

#include <memory> 
#include <iostream> 
  
int main() 
{ 
    auto sp1 = std::make_shared<int>(5);
    std::cout << std::boolalpha;
    std::cout << "sp1.unique() == " << sp1.unique() << '\n'; 

    std::shared_ptr<int> sp2 = sp1; 
    std::cout << "sp1.unique() == " << sp1.unique() << '\n'; 
}

:

sp1.unique() == true
sp1.unique() == false

use_count

shared_ptr,
(public -) []







(C++20)

(C++20)
(C++11)





(C++20)


/

(C++11)
(C++11)
(C++11)
(C++17)

-
shared_ptr::shared_ptr
shared_ptr::~shared_ptr
shared_ptr::operator=

shared_ptr::reset
shared_ptr::swap

shared_ptr::get
shared_ptr::operator*shared_ptr::operator->
shared_ptr::operator[] (C++17)
shared_ptr::use_count
shared_ptr::unique ( C++20*)
shared_ptr::operator bool
shared_ptr::owner_before
,
std::swap
make_sharedmake_shared_for_overwrite (C++20)
allocate_sharedallocate_shared_for_overwrite (C++20)
static_pointer_castdynamic_pointer_castconst_pointer_castreinterpret_pointer_cast (C++17)
get_deleter
operator==operator!=operator<operator<=operator>operator>=operator<=> ( C++20)( C++20)( C++20)( C++20)( C++20)(C++20)
operator<<
atomic_xxx functions ( C++20)
std::atomic<std::shared_ptr> (C++20)
std::hash
(C++17)

cppreference.com

std::shared_ptr::unique