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From: jtorjo2007 on 25 Nov 2007 18:14
> I'm seeking comments about this solution, especially about the
> heuristic (if someone has an experience on a system where the
> heuristic would not work at all for example) though any suggestion /
> correcting is welcome.
>

If I read you correctly, this has been developed before:
http://www.boost.org/libs/utility/call_traits.htm

Best,
John


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From: courpron on 25 Nov 2007 18:20
On 26 nov, 01:14, Mathias Gaunard <loufo...(a)gmail.com> wrote:
> On 25 nov, 18:07, courp...(a)gmail.com wrote:
>
> > if ( sizeof(Type) > sizeof(Type*) )
> > pass by ref to const
> > else
> > pass by value
>
> This is quite naive.
> The type could be small but have an expensive copy constructor.
>
> I suppose you only want to pass-by-value for objects with trivial copy
> constructor.

Yes, you guessed correctly, I'm interesting only about POD / data
structures that can be copied in a raw way.
I generalized too much the problem in my post and I forgot to mention
that aspect.

> Also, it may be interesting to pass objects sized of two words by
> value too.

Indeed, I thought about (sizeof(Type) > sizeof(Type)*n) where n = 2
or even 3 or 4 could work, but this is somewhat less provable than the
first condition. In fact I would want to always have an equal or
superior performance over just a pass by value, or just a reference to
const.

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From: wijnand on 25 Nov 2007 19:42
Hi Alexandre,

courp...(a)gmail.com wrote:
> I'm seeking comments about this solution, especially about the
> heuristic (if someone has an experience on a system where the
> heuristic would not work at all for example) though any suggestion /
> correcting is welcome.
>

There is already a Boost library trying to solve this:
http://www.boost.org/libs/utility/call_traits.htm

kind regards,
Wijnand

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