Alignment (was: Structure Member Padding)

[Joseph S. D. Yao]

In article <1990Aug8.012908.28364 at sq.sq.com> msb at sq.sq.com (Mark Brader) writes:
>1.6 says that any object is a contiguous sequence of bytes, each of which
>is individually addressable.  3.3.3.4 forces the size of type char to be
>exactly 1 byte.  

...

>I can't take "contiguously allocated" to mean anything else but that
>the object declared by "char y[4];" occupies exactly 4 bytes, which have
>consecutive addresses; sizeof y must be 4.

In recent years, for some reason, people have been assuming that "byte"
means "eight bits" (bit = binary unit of information).  The more
general definition that I learned at the beginning of my introduction
to computers was that it was a group of [contiguous] bits.  This was
reinforced by the existence of byte-handling instructions on machines
like the now-venerable PDP-10 and its successors.  For these instruc-
tions, one had to specify not only a byte address, but also a starting
bit and a size (0-36).

I am sure that the ANSI standard has a reasonable definition of "byte",
probably the one that Doug gave ... from where I'm sitting, I just
can't see a copy of it ...

	Joe Yao				jsdy at hadron.COM
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