Re: Why next/prev for iterators in C++0x?

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 25 Apr 2011 09:02:07 -0700 (PDT)

Message-ID:

<2376a7f7-f04d-4cf4-a4e1-2f6c29247438@34g2000pru.googlegroups.com>

On Apr 24, 9:02 am, "crea" <n...@invalid.com> wrote:

"Howard Hinnant" <howard.hinn...@gmail.com> wrote in message

news:c3808703-28c5-457e-acb4-4112f12862b4@d12g2000vbz.googlegroups.com...
On Apr 23, 5:53 pm, Marc <marc.gli...@gmail.com> wrote:

" ...
    for (ForwardIterator1 j = std::next(i); j != last1; ++j)
        if (pred(*i, *j))
            ++c1;
"

Just a small comment: I just read an article to say , that we
dont really (always) need to do ++j, but can do j++. The
reason is that the computer can trim the code many times when
it compiles. Also testing showed that there was no big
difference even if j++ was used. But I have to read the
article again...
   On the other hand, I dont know why using ++j would be not good.

In practice, there's no valid technical reason for preferring
one over the other---it's just a question of which one you like
best. Politically speaking, however... some noted authors have
claimed otherwise, and have influences a large number of
programmers; it's easier to just use ++j than to argue with
them. (FWIW: K&R favored j++, and at least in the earlier
versions of his books, so did Stroustrup, so for older
programmers, who learned from the original masters, j++ often
seems more natural. Just because we've seen it more often,
however; not for any technical reason.)

--
James Kanze

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