> On Apr 27, 2015, at 2:21 AM, Roberto E. Vargas Caballero <k...@shike2.com> > wrote: > > Again, read [1], section "The use of pointers". Maybe you don't agree with > it, but almost > all the people here agree with it.
Your link shows the use of `node[i].left` as a perfectly valid example when an
array is being indexed. And since `cp` is not a structure, there is not enough
single-line context to know what `cp` means in the original example.
The use of cp in such a simple loop is not, again to quote your link, "code
containing many similar, complex expressions that evaluate to elements of a
data structure”, so the use of a pointer is not really justified by just
quoting the article. Again, this is without seeing the surrounding code itself,
just the snippets presented in the grandparent conversation.
> ANSI C standard, section 3.3.8 (Relational operators):
>
[…]
>
> It is no casuality they added this rule to the standard. They added
> it because is the idiomatic way of running over an array in C. Of
> course CS teachers that liked pascal don't teach it anymore when
> they were forced to move to C, but it is the best way for experienced
> C programmers. Get used to it.
The code in question was not comparing Q against P+1, it was comparing Q
against P, where `P = &array[len+1]`, which is a subtly different case. The
first increments a pointer by the size of one element, while the second
accesses the array element just after the end of the array and obtains a
reference to that point in memory. The first is dealing with a number in
memory, the second is accessing memory to get a pointer to it. Nothing in the
3.3.8 section affects this.
To make the loop code in question obey the Q < P+1 idiom, it would have to look
more like:
for (cp = colors; cp < &colors[LEN(colors)] + 1; cp++)
I still prefer the `cp - colors < LEN(colors)` version, myself.
-G
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