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Re: Pointer to undeclared structure-type considered ok?


Hi Nick,

>In what sense is the "struct bar" type defined?

None.

I did not say that the "struct bar" type is defined.

It's also not used or referenced.

>Because if "struct bar" is not defined, then how can "struct bar *" be defined?

The definition of "struct bar*" is not dependent upon the definition of "struct bar".

Pointers are fundamental data types.

>Is it ok to to have pointer-type whose base type is not (or incompletely) defined?

Assuming you are using "base type" in a contextually liberal sense for "reference type", instead of the inheritance sense of C++...

Yes, it's ok -- for a lot of operations. What you are dealing with is a pointer. A pointer is a fundamental data type.

What you cannot do is increment/decrement the pointer, use array access, or access the (undefined, unknown) members, or dereference the pointer in any other fashion[1].

--Eljay

[1] Well, you can dereference it using casting techniques to a defined, known type. But that's slight-of-hand.


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