Std::shared_ptr::operatorbool (3) Linux Manual Page

std::shared_ptr<T>::operatorbool – std::shared_ptr<T>::operatorbool

Synopsis

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

// Run this code

#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);
}

Output:

ptr is not a valid pointer.
*ptr=7

std::shared_ptr::operatorbool (3) Linux Manual Page