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std::shared_ptr::use_count

From cppreference.com
< cpp‎ | memory‎ | shared ptr
 
 
 
 
 
long use_count() const;

Returns the number of different shared_ptr instances (this included) managing the current object. If there is no managed object, 0 is returned.

Contents

[edit] Parameters

(none)

[edit] Return value

the number of shared_ptr instances managing the current object or 0 if there is no managed object.

[edit] Example

#include <memory> 
#include <iostream> 
 
void fun(std::shared_ptr<int> sp)
{
    std::cout << "fun: sp.use_count() == " << sp.use_count() << std::endl; 
}
 
int main() 
{ 
    std::shared_ptr<int> sp1 {std::make_shared<int>(5)};
    std::cout << "sp1.use_count() == " << sp1.use_count() << std::endl; 
 
    fun(sp1);
}

Output:

sp1.use_count() == 1
fun: sp.use_count() == 2

[edit] See also

checks whether the managed object is managed only by the current shared_ptr instance
(public member function) [edit]