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From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: sizeof() confusion
Message-ID: <27498@mimsy.umd.edu>
Date: 7 Nov 90 04:13:54 GMT
References: <9156@latcs1.oz.au> <58808@microsoft.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 24

In article <58808@microsoft.UUCP> dans@microsoft.UUCP (Dan SPALDING) writes:
>In C, the base of an array is synonomous with a pointer to an element (the
>base element) of that array.

Not exactly.  A precise definition is:

   Given an object of type `array N of T' placed in a value context, a
   C system must produce a value of type `pointer to T' which points
   to the first (0th) element of that array.

`Array' and `pointer' are completely different, but one happens to be
converted to the other IN VALUE CONTEXTS.  (A `value context' is any
place where you need the value of an expression.  Thus, given

	a = b;

`b' is in a value context, but `a' is not, because this puts the value
of b into a, but says nothing about the value of a.)  C happens to have
about three contexts which are not value contexts: declarations, left
hand side of assignment operators (including `i' in `++i' and `i++'),
and following `sizeof'.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 405 2750)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris