Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!psuvax1!wuarchive!uunet!microsoft!jimad
From: jimad@microsoft.UUCP (Jim ADCOCK)
Newsgroups: comp.std.c++
Subject: aliases, ptr coercions, and optimizations
Message-ID: <56170@microsoft.UUCP>
Date: 30 Jul 90 19:50:35 GMT
Reply-To: jimad@microsoft.UUCP (Jim ADCOCK)
Organization: Microsoft Corp., Redmond WA
Lines: 15

Request for Clarification and a General Proposal:

I claim there is a need for clarification in terms of what kinds of ptr
casts are legal in the face of an optimizing compiler.  For example, does:

	foo* fooptr = &(bar.fooMember);

poison fooMember, the labeled section fooMember is in, the class derivation
that fooMember is in, or all of bar?

My general proposal is that C++ be very restrictive in terms of what pointer
casts are "guaranteed" to work, allowing for maximum compiler optimizations,
while minimizing the pointer hacks that are "guaranteed" to work.  IE,
good C++ citizens should get well optimized code, but C++ hacker code may
not work at all.