Re: One more foolishness of the C++ Standard

From:

Ulrich Eckhardt <eckhardt@satorlaser.com>

Newsgroups:

microsoft.public.vc.language

Date:

Fri, 22 Jan 2010 09:08:26 +0100

Message-ID:

<q03o27-ijd.ln1@satorlaser.homedns.org>

Vladimir Grigoriev wrote:

The problem is the same as with std::min and std::min_element. I do not
see any reasonable explanation why these restrictions were adopted. It
seems that this shrinks functionality of C++ without any serious reason.

What is "this"? Further, you must know that the STL wasn't developed very
far at the point where it was incorporated in the C++ standard. This
explains at least a few areas that could be improved.

For example all that I have heard here relative to std::min is some
references to sort algorithms. However I do not see a relation
between std::min and sort algorithms..

I do, std::min returns the first element that a sequence would have after
std::sort'ing it, simple as that. In that sense, it makes sense for
std::min to require the same semantics of the predicate as std::sort.

BTW: why did you quote all the following text while not even referring to
it? It makes it hard to guess what you mean....

Vladimir Grigoriev

"Ulrich Eckhardt" <eckhardt@satorlaser.com> wrote in message
news:5acm27-40c.ln1@satorlaser.homedns.org...

Vladimir Grigoriev wrote:

There is no a great sense to compare some size_t value with an object of
type Person. This comparison has no sense. It is a general situation
when converting some object of a class to an integral type has sense
while converting an integral type to an object has no sense. For this
purpose the explicit reywoard was introduced. The same is valid for
operators. i.e. sometimes a op b has sense while b op a has no sense.

I'd say whether switching operands still has sense depends on the
operator.
For an equality comparison, I expect it to be fully commutative.
Similarly for inequality, while e.g. greater behaves slightly different.

Are you really implying that a==b makes sense when b==a doesn't? I
already voiced my opinion on comparison of a person with an ID: "I
wouldn't overload operator== for that."

Uli

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Uli

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