Re: [boost] Re: Proposed smart_handle library

[Gregory Colvin]

I'm generally less afraid of automatic conversions than many others, and
dropped them from auto_ptr, and later from shared_ptr, only under 
duress.
I like them for wrapper classes because they make it possible to drop 
the
wrappers directly into existing code that uses the wrapped types.  I 
like
the terseness too, but then I am perverse enough to prefer &*p to 
p.get().

On Monday, Jul 21, 2003, at 22:27 America/Denver, John Madsen wrote:

"Eugene Lazutkin" <[EMAIL PROTECTED]> wrote:
Inline.

"John Madsen" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
If you can convince most of the people on this list to provide an
automatic
conversion, more power to you.  I still maintain that avoiding hard 
to
diagnose
errors is worth much more than saving 6 characters of typing.
I am not trying to convince anybody in overall goodness of automatic
conversion. :-) I am asking question, which is still ignored: what 
"hard to
diagnose errors" do you envision for smart handles??? Reference to 
some
dogma would suffice too. ;-)

For a discussion of why user defined conversions are a bad idea (not
always,
but most of the time), see More Effective C++, Item 5.
I've read it when it was printed. I know author's reasons. And I 
agree with
most of them. The question is: how do they apply in _this particular 
case_?



I am not ignoring the question.  The point is that it is hard to guess 
what
errors might occur.  I did reference some dogma as well.  I take 
Meyers' point
to be that automatic conversions can sometimes produce surprising 
effects.
Those effects may result in code that does something other than what 
it appears
to do.  Thus, *unless there is a very good reason*, avoid automatic
conversions.  That is what I did.  Your reason for including them, 
i.e.,
avoiding typing, does not strike me as a good one.

John

P.S.  Of course, if you want Scott Meyers on your side in this one, 
just look
at Item 9 in the same book, where he does exactly what you're 
suggesting :-).
Against his own better judgment IMHO.
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