Old problem with performance

[Bill Baxter]

On Sun, Feb 22, 2009 at 5:10 AM, Denis Koroskin <2korden at gmail.com> wrote:
> On Sat, 21 Feb 2009 21:49:46 +0300, Bill Baxter <wbaxter at gmail.com> wrote:
>
>> On Sun, Feb 22, 2009 at 1:02 AM, Weed <resume755 at mail.ru> wrote:
>>>
>>> Bill Baxter пишет:
>>>>
>>>> 2009/2/21 Weed <resume755 at mail.ru>:
>>>>>
>>>>> Weed пишет:
>>>>>>
>>>>>> Bill Baxter пишет:
>>>>>>
>>>>>>> Why don't you just show us the class in the way you would like to
>>>>>>> write it in C++, and we'll show you how to write it in D, or finally
>>>>>>> agree with you that it's not possible.   But as long as you continue
>>>>>>> to be hand-wavy about "common base classes" we're at a bit of an
>>>>>>> impasse.  So far everyone thinks D can do what you want it to do
>>>>>>> based
>>>>>>> on your vague descriptions.
>>>>>
>>>>> As I said, you can write everything using "goto" and "if".
>>>>>
>>>>> ...But why you do not like the original example of this thread?
>>>>
>>>> Please post again.  I don't seem to recall any detailed example.
>>>>
>>>> --bb
>>>
>>>
>>> http://www.digitalmars.com/pnews/read.php?server=news.digitalmars.com&group=digitalmars.D&artnum=83506
>>
>> You should use a struct there!   Your code does not show you doing
>> anything that would even remotely suggest using a class is worthwhile.
>>  You're doing value operations on value types.  That's what structs
>> are for.
>>
>> --bb
>
> That's what *everyone* tells him!

I am vaguely open to the possibility that he has a point.  FLENS uses
inheritance, for instance.  But I don't recall what the intent of that
inheritance was in FLENS, exactly.  I more or less ported it to D
without that, though, so I guess I didn't find it to be essential.
See this:
  http://flens.cvs.sourceforge.net/viewvc/flens/FLENS/matvec/densevector.h?revision=1.36&view=markup
Versus this:
  http://www.dsource.org/projects/multiarray/browser/trunk/multiarray/dflat/DenseVector.d

Weed, if you want to make a real argument, that would be a good place
to start.  Investigate why and how FLENS uses inheritance.

--bb