On 11/10/2010 11:47 PM, Patrick Horgan wrote: > On 11/10/2010 01:16 AM, Andrew Haley wrote: >> ...elision by patrick... >> The aliasing rules are nothing to do with C99: they have always >> been in Standard C. > Thanks. I didn't know that (or if I did I forgot somewhere). I just > really noticed people talking about strict aliasing lately (the last 3 > or 4 years I've seen it a lot). Do you think it's because the compilers > are getting better at complaining about type-punning that's outside of > the aliasing rules? I suspect so. >> You really ought to refer to the standard, so people can see the >> official rules for themselves. > That's a good point. I suppose I could put a link to a publicly > available draft version of the C and the C++ standards. Is there > anyplace now where a final (non-draft) version of some version of the C > and the C++ standards if freely available to the public? No chance! The official versions cost money, the final drafts don't. There's no difference in the text. http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf > I've seen though that often people go to the standards and look at the > aliasing rules with a strange world view and get more confused about > aliasing and not less. That's really the point of my document, to get > regular developers to understand what aliasing is before they go and > look at the rules so they understand what they're reading. Do you > suppose it would be appropriate to refer them to the standards at the > end of the top section, before I start the type-punning section? I'd suggest proper references: every time you say something, point to to the section in the standard by giving a paragraph number. Andrew.
