std::shared_ptr<T>::operatorbool (3) - Linux Man Pages

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

NAME

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

See also


    returns the stored pointer
get (public member function)