Xref: utzoo comp.std.c++:140 comp.std.c:3477
Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!lupine!rfg
From: rfg@NCD.COM (Ron Guilmette)
Newsgroups: comp.std.c++,comp.std.c
Subject: Re: constant expressions
Message-ID: <1192@lupine.NCD.COM>
Date: 15 Aug 90 06:38:29 GMT
References: <5930@darkstar.ucsc.edu> <1916@tkou02.enet.dec.com>
Followup-To: comp.std.c++
Organization: Network Computing Devices, Inc., Mt. View, CA
Lines: 18

In article <1916@tkou02.enet.dec.com> diamond@tkou02.enet.dec.com (diamond@tkovoa) writes:
>In article <5930@darkstar.ucsc.edu> daniel@terra.ucsc.edu () writes:
>
>>Should a translator identify 1-1 as ``a constant expression evaluating
>>to zero,'' (even absent optimization)?
>
>I have added comp.std.c to the distribution for this article, because
>the C standard is almost vague on this as well.  If C++ maintains
>compatibility with C here, then my best guess is:
>  A translator does not have to compute the constant expression...

Neither the C standard nor E&S are vague about this at all.  Clearly,
1-1 is "a constant expression evaluating to zero".
-- 

// Ron Guilmette  -  C++ Entomologist
// Internet: rfg@ncd.com      uucp: ...uunet!lupine!rfg
// Motto:  If it sticks, force it.  If it breaks, it needed replacing anyway.