From: utzoo!decvax!cca!mo@Lbl-Unix@sri-unix
Newsgroups: net.unix-wizards
Title: Re:  Information on Unix/Vax peculiarities
Article-I.D.: sri-unix.4609
Posted: Sat Dec  4 12:04:55 1982
Received: Mon Dec  6 08:08:23 1982

From: mo at Lbl-Unix (Mike O'Dell [system])
Date: 30 Nov 1982 23:22:18-PST
In general, C assumes (char *) is the fattest pointer, or rather,
that (char *) is a type to which other pointers (and some 
useful range of ints) can always be cast without information
loss.  Even on very strange machines this is true.
By very strange, I mean word-addressed wonders with odd numbers
of chars/word, or machines with 16 or 18-bit int pointers and
19-bit char pointers.  There are C compilers for both of these
machines which work quite nicely with this restriction.

On the other hand, larger data objects (like doubles) may require
larger alignment, so (char *) is usually the "most resolved" pointer
(takes the most number of bits to distinguish different objects)
and (double *) is likely the most boundary-aligned.  These are not
hard and fast rules, but are true in all the C compilers I have seen.

DMR, please correct any mispeaks.

	-Mike