CODEWITHSUNDEEP
c++c++11nullptr
chaosink
chaosink

Reputation: 1483

How is nullptr defined?

In Effective Modern C++, "Iterm 8: Prefer nullptr to 0 and NULL.", Page 59, it says:

nullptr's actual type is std::nullptr_t, and, in a wonderfully circular definition, std::nullptr_t is defined to be the type of nullptr.

A wonderfully circular definition?

How that comes?

Upvotes: 4

Views: 1795

Answers (1)

bipll
bipll

Reputation: 11950

In brief, nullptr is a value that can be assigned to a pointer to any type, and it is false in boolean context (unlike most pointers that are results of new/malloc, or referencing a valid object), and despite itself being a valid pointer, dereferencing it results in UB, as does in/decrementing it, and it is a sole value of a singleton type nullptr_t.

Something like this.

Upvotes: 2

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