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Subject: Re: [boost] [chrono] patch for VC9 duration conversions
From: Vicente Botet (vicente.botet_at_[hidden])
Date: 2011-02-23 07:40:00

David Deakins wrote:
> Currently the enable_if expressions that restrict implicit duration type
> conversion to only conversions that will not reduce resolution are
> disabled on VC9 because they trigger a compiler error. I have come up
> with a slight adjustment to the expression that VC9 appears to be able
> to digest more favorably. Attached is a patch. I also opened ticket
> 5214 in Trac with this information. Vincent, if the patch looks good,
> let me know if you want to apply it or if you would like me to.
> -Dave


thanks for looking at this VC9 issue. And congratulation for the first
Chrono ticket I'm aware off :)

I was unable to find out why VC9 had some problems with these enable_if

I see that you have removed 2 cases, but there are others. Have you tried to
analyze them?

The patch seem good to me except that we are adding a ratio detail. Maybe it
will be better to add the is_evenly_divisible_by metafunction in the details
of Boost.Chrono for the moment.

Please be free to apply the patch yourself. I will try to see if similar
workarounds can solve the other cases.

Many thanks Dave,

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