nullptr, the pointer literal

Syntax

Explanation

The keyword nullptr denotes the pointer literal. It is a prvalue of type std::nullptr_t. There exist implicit conversions from nullptr to null pointer value of any pointer type and any pointer to member type. Similar conversions exist for any null pointer constant, which includes values of type std::nullptr_t as well as the macro NULL.

Example

#include <cstddef>
#include <iostream>
 
template<class F, class A>
void Fwd(F f, A a)
{
    f(a);
}
 
void g(int* i)
{
    std::cout << "Function g called\n";
}
 
int main()
{
    g(NULL);           // Fine
    g(0);              // Fine
 
    Fwd(g, nullptr);   // Fine
//  Fwd(g, NULL);  // ERROR: No function g(int)
}

Function g called
Function g called
Function g called

Keywords

nullptr.

See also

References

• C++11 standard (ISO/IEC 14882:2011):
• 4.10 Pointer conversions [conv.ptr]