Re: Postfix is slower than postfix: how likely?

From:
"kanze" <kanze@gabi-soft.fr>
Newsgroups:
comp.lang.c++.moderated
Date:
19 May 2006 23:29:25 -0400
Message-ID:
<1148026471.267155.97780@j73g2000cwa.googlegroups.com>
Seungbeom Kim wrote:

Francis Glassborow wrote:

post fix requires a copy unless you are asking that in the
free-standing case the compiler treats them identically.


It is commonly believed that the postfix operator SHOULD make
a copy, but should it really? It can also return a cheap proxy
that increments the subject upon destruction, in case the
subject is expensive to copy.


     [...]

Maybe this could be a standard idiom for implementing postfix
operators? :)


It's a nice idea; I like it a lot. But for iterators, postfix
increment and decrement aren't the only places copying occurs.
The entire STL is based on the premise that iterators (and
functional objects) are cheap to copy. Violate that, and you
will probably have performance problems, regardless of what you
do with postfix increment and decrement.

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