std::shared_ptr<T>:: operator bool

Checks if * this stores a non-null pointer, i.e. whether get ( ) ! = nullptr .

Parameters

(none)

Return value

true if * this stores a pointer, false otherwise.

Notes

An empty shared_ptr (where use_count ( ) == 0 ) may store a non-null pointer accessible by get() , e.g. if it were created using the aliasing constructor.

Example

#include <iostream>
#include <memory>
 
void report(std::shared_ptr<int> ptr) 
{
    if (ptr)
        std::cout << "*ptr=" << *ptr << "\n";
    else
        std::cout << "ptr is not a valid pointer.\n";
}
 
int main()
{
    std::shared_ptr<int> ptr;
    report(ptr);
 
    ptr = std::make_shared<int>(7);
    report(ptr);
}

ptr is not a valid pointer.
*ptr=7

See also