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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: usecases of void foo(char **b) {}
Date: Sun, 06 Nov 2016 14:06:44 -0800
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Ben Bacarisse <ben.usenet@bsb.me.uk> writes:
> Keith Thompson <kst-u@mib.org> writes:
>
>> Richard Heathfield <rjh@cpax.org.uk> writes:
>> [...]
>>> Uh, the only rule (and it isn't a particularly arcane rule) is that, 
>>> when used in a value context, the name of an array is treated as a 
>>> pointer to its first element. That's not /such/ a big deal, surely?
>> [...]
>>
>> Warning: I'm about to pontificate at some length over something
>> that's not greatly significant.
>
> ... and I'm about to make it worse ...
>
>> I've seen the rule stated that way before.  It's not terribly far
>> from being correct, but it does misstate the rule.
>>
>> The rule, as I know you know, is that an expression of array type
>> (not just the name of an array) is "converted" ("adjusted" would
>> have been a better term) to be an expression of pointer type,
>> unless it's in one of three contexts: the operand of sizeof, the
>> operand of unary "&", or a string literal in an initializer used
>> to initialize an array object.  That's still not particularly arcane.
>
> That list now includes the operand of _Alignof (unless that changed in
> the final adjustments between draft n1570 and C11).
>
> <snip>

It did change between N1570 and C11.  The inclusion of _Alignof was
an error in N1570.  In fact, _Alignof, unlike sizeof, can only be
applied to a parenthesized array type, not to an array expression.
The published C11 standard corrected that error.  (The reason for
that gratuitous difference is another matter.)

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"