std::shared_ptr<T>::operator bool

Declarations

explicit operator bool() const noexcept;

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);
}

Result

ptr is not a valid pointer.
*ptr=7