[openbeos] Re: Coding Suggestion -- Templates, Iterators


Your loop macro doesn't work.  (elem++)
And anyway, it doesn't get rid of the iterator declaration.
That is more effort than it is worth.

-Max

----- Original Message ----- 
From: "Daniel Reinhold" <danielr@xxxxxxxxxxxxx>
To: "OpenBeOS mailing list" <openbeos@xxxxxxxxxxxxx>
Sent: Saturday, October 27, 2001 1:47 PM
Subject: [openbeos] Coding Suggestion -- Templates, Iterators


> 
> At the risk (ah heck, certainty) of starting a language war, I have a
> couple of suggestion regarding coding style with C++.
> 
> I came across the following code today (actually its from CppTest):
> 
> void TestSuite::run (TestResult *result)
> {
>     for (std::vector<Test *>::iterator it = m_tests.begin ();
>             it != m_tests.end ();
>             ++it) {
> // loop code
>     }
> 
> }
> 
> (I've snipped out the loop code)
> 
> A couple of things occur to me as I stare at this code (besides the
> fact that I'm not crazy about C++). One is that the template
> declaration syntax is often extremely awkward to read. In many cases,
> it makes sense to typedef these buggers into something more friendly.
> In this example, I would do:
> 
> typedef std::vector<Test *>::iterator TestIterator;
> 
> Another thing is that iterators are pretty common, so I think having a
> standard macro for traversing with one would be very useful. Here's my
> suggestion:
> 
> #define foreach(elem,set) for (elem = set.begin (); elem != set.end ();
> ++elem)
> 
> Oh, I know, I can hear the groaning out there... "we don't use #define
> macros -- that's old-style, icky C crap that we sophisticated C++
> programmers don't use". Maybe, but I still think macros are extremely
> useful when used sparingly and judiciously. They're awfully good at
> hiding uglies.
> 
> Now using those two code snippets above, I can rewrite the example
> (using OpenTracker formatting) as follows:
> 
> void
> TestSuite::run (TestResult *result)
> {
> TestIterator i;
> foreach (i, m_tests) {
> // loop code
> }
> }
> 
> Now that's a bit cleaner/clearer. When reading the iterator loop, you
> have to mentally put the word "in" in there. IOW, read it as "for each
> i in m_tests".
> 
> So whadya think? Love it? Hate it?
> 
>

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