nullptr, the pointer literal (since C++11) (original) (raw)

[edit] Syntax

| | | | | ----------- | | | | nullptr | | | | | | |

[edit] 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.

[edit] Keywords

nullptr

[edit] Example

Demonstrates that nullptr retains the meaning of null pointer constant even if it is no longer a literal.

#include #include template constexpr T clone(const T& t) { return t; } void g(int*) { std::cout << "Function g called\n"; } int main() { g(nullptr); // Fine g(NULL); // Fine g(0); // Fine g(clone(nullptr)); // Fine // g(clone(NULL)); // ERROR: non-literal zero cannot be a null pointer constant // g(clone(0)); // ERROR: non-literal zero cannot be a null pointer constant }

Output:

Function g called Function g called Function g called Function g called

[edit] References