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> Concrete example: if you declare
>
> int genxComment(genxWriter w, const utf8Byte * text);
>
> then a user of the genx API can pass either a 'const utf8Byte *'
> or a plain 'utf8Byte *' to the routine, without any compiler
> warnings.
>
> genxComment() in turn can pass 'text' to strcpy (as the second
> argument), etc., also without any compiler warnings. [*]
>
> Conversely, if you declare:
>
> int genxComment(genxWriter w, utf8Byte * text);
>
> then users of the API can *only* pass plain, non-const 'utf8Byte *'s
> to the routine. If they happen to have a 'const utf8Byte *',
> then *they* need to do a cast, or copy to a non-const buffer,
> or perform some other gyration.
Joe,
the problem is that it is not so. Take an ANSI C compiler, turn all warning
on and try it.
If one declares an interface where no const is used at all, anyone can used
without casts.
The only difference for API is for callbacks, function variables with 'const'
in their arguments; and nowhere else.
David Tolpin
PS The worst thing about 'const' in C is that few people can say when it is
needed without consulting the Manual. C is good enough without 'const'.
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