Is a pointer to an array of unknown size incomplete?

Question

3.9/6 N3797:

[...]

The type of a pointer to array of unknown size, or of a type defined by a typedef declaration to be an array of unkno

Answer 1

I think this wording is defective. In your code:

 int (*a)[];

the type of a is actually complete. The type of *a is incomplete. It seems to me (as dyp says in comments) that the intent of the quote was to say that there is no way that later in the program, *a will be an expression with complete type.

Background: some incomplete types can be completed later e.g. as suggested by cdhowie and dyp:

extern int a[];
int b = sizeof a;  // error
int a[10];
int c = sizeof a;  // OK

However int (*a)[]; cannot be completed later; sizeof *a will always be an error.