std::shared_ptr::operator bool

From cppreference.com
< cpp‎ | memory‎ | shared ptr
 
 
 
Dynamic memory management
Uninitialized storage
(C++17)
(deprecated since c++17)
(deprecated since c++17)
(deprecated since c++17)
Garbage collection support
Miscellaneous
(C++11)
(C++11)
C Library
Low level memory management
 
 
explicit operator bool() const;

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.

Exceptions

noexcept specification:  
noexcept
  

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>
 
typedef std::shared_ptr<int> IntPtr;
 
void report(IntPtr ptr) 
{
    if (ptr) {
        std::cout << "*ptr=" << *ptr << "\n";
    } else {
        std::cout << "ptr is not a valid pointer.\n";
    }
}
 
int main()
{
    IntPtr ptr;
    report(ptr);
 
    ptr = IntPtr(new int(7));
    report(ptr);
}

Output:

ptr is not a valid pointer.
*ptr=7

See also

returns the stored pointer
(public member function)