Re: [C or C++] Is this legal? sizeof *p

From: Jason (spacenjasset_at_yahoo.co.uk)
Date: 01/04/04 

Date: Sun, 4 Jan 2004 12:22:30 -0000

"Jack Klein" <jackklein@spamcop.net> wrote in message
news:2csevvcntm2up8b4vm4e6khlnlbh366tp2@4ax.com...
...
> On Sat, 03 Jan 2004 17:17:30 -0500, Jeff Schwab <jeffplus@comcast.net>
> In C++, and in C except for one special case in C99, the sizeof
> operator is guaranteed not to evaluate its operand, merely use the
> operand to identify the type and hence the size.
...

Thanks, I suspected that be the case. I suppose that this sort of usage is
to be discouraged as a matter of readability. Although it does have the
advantage that if the type changes the sizeof *p need not.

Relevant Pages

  • Re: Null terminated strings: bad or good?
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    (comp.std.c)
  • Re: Regarding sizeof Operator
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    (comp.std.c)
  • Re: Null terminated strings: bad or good?
    ... I think I just found a paragraph in the standard that should solve this ... This should apply when the operand of sizeof is such that the result ... sizeof on an overly large value were undefined behavior, ...
    (comp.std.c)
  • Re: Sizeof question
    ... |> | sizeof returns the number of chars that array occupies. ... | On the most common system, a char is 1 byte though. ... operand, which may be an expression or the parenthesized ... operand is a variable length array type, ...
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