std::shared_ptr::unique
From cppreference.com
< cpp | memory | shared ptr
| bool unique() const noexcept; |
(deprecated in C++17) (removed in C++20) |
|
Checks if *this is the only shared_ptr instance managing the current object, i.e. whether use_count() == 1.
Parameters
(none)
Return value
true if *this is the only shared_ptr instance managing the current object, false otherwise.
Notes
This function was deprecated in C++17 and removed in C++20 because use_count is only an approximation in multithreaded environment (see Notes in use_count)
Example
Run this code
#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'; }
Output:
sp1.unique() == true sp1.unique() == false
See also
returns the number of shared_ptr objects referring to the same managed object (public member function) |