Re: [boost] [Review] Formal Review of Proposed Boost.Ratio Library

Subject: Re: [boost] [Review] Formal Review of Proposed Boost.Ratio Library
From: vicente.botet (vicente.botet_at_[hidden])
Date: 2010-10-07 11:57:32

----- Original Message ----- 
From: "Stewart, Robert" <Robert.Stewart_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Thursday, October 07, 2010 3:32 PM
Subject: Re: [boost] [Review] Formal Review of Proposed Boost.Ratio Library

> Howard Hinnant wrote:
>> >> From: "Stewart, Robert" <Robert.Stewart_at_[hidden]>
>> >>
>> >>> The use of enable_if to control the contexts in which the
>> >>> copy constructor and copy assignment operator apply goes
>> >>> beyond the standard's specification.  That means boost::ratio
>> >>> behaves differently than will std::ratio.  I think this will
>> >>> lead to surprising results when one transitions from one to
>> >>> the other.
> [snip]
>> I would be tempted to consider this extension to the standard
>> semantics based on its technical merits alone, motivated by
>> Beman's more general policy statement:
>>
>> On Oct 2, 2010, at 8:11 AM, Beman Dawes wrote:
>>
>> > One of the advantages of Boost is that we can add extensions and get
>> > user experience before something gets standardized. That's very
>> > helpful to the C++ committee.
> 
> That's a fine approach, but it should be treated as an extension: the user should have to enable it.  That avoids surprises when migrating to std::ratio (as it is defined presently).

If everyone agree, I can add define that let the user use the extension, so we can have both.

Vicente