Messages in this thread | | | Date | Wed, 27 Jun 2007 21:26:28 +0900 | From | Neil Booth <> | Subject | Re: [PATCH 16/16] fix handling of integer constant expressions |
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Al Viro wrote:-
> Egads... After rereading that... What a mess. > > int foo(void) > { > static int a[1][0,2]; > } > > is, AFAICS, allowed. Reason: > int a[0,2] > is a VLA due to 6.7.5.2[4] (0,2 is not an ICE). However, due to the language > in the same section, > int a[1][0,2] > is *not* a VLA, since (a) 2 is an ICE and (b) its element type "has a known > constant size" (it does - the value of 0,2 is certainly guaranteed to be 2). > I.e., it's VM type, but not a VLA. I.e. only the first part of 6.7.5.2[2] > applies and we are actually fine. > > So we can have a static single-element array of int [0,2], but > not a plain static int [0,2]. Lovely, that...
DR 312 clarified the meaning of "known constant size"
http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_312.htm
in the sensible way, thankfully, so your example is actually invalid.
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