PHWinfo - Afficher un message - Getting sizeof an anonymous struct declared inside a union

17/10/2007, 21h49

vipvipvipvip.ru@gmail.com writes:
> On Oct 17, 6:07 pm, David Resnick <lndresn...@gmail.com> wrote:
>> Is the second legitimate? It compiles without complaint, but looks
>> dodgy.
> Yes it is.
> Consider the following:
> int *p;
> printf("sizeof(*p) == sizeof(int) == %zu\n", sizeof *p);
> This would've been invalid code if what p pointed to was really
> accessed.

Yes, it would have. Fortunately, the argument to sizeof is never
evaluated unless it's a VLA.

--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

17/10/2007, 21h49	#5
Keith Thompson Messages: n/a Hébergeur:	Re: Getting sizeof an anonymous struct declared inside a union vipvipvipvip.ru@gmail.com writes: > On Oct 17, 6:07 pm, David Resnick <lndresn...@gmail.com> wrote: >> Is the second legitimate? It compiles without complaint, but looks >> dodgy. > Yes it is. > Consider the following: > int p; > printf("sizeof(p) == sizeof(int) == %zu\n", sizeof p); > This would've been invalid code if what p pointed to was really > accessed. Yes, it would have. Fortunately, the argument to sizeof is never evaluated unless it's a VLA. -- Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst> San Diego Supercomputer Center <> <http://users.sdsc.edu/~kst> "We must do something. This is something. Therefore, we must do this." -- Antony Jay and Jonathan Lynn, "Yes Minister"