----- Original Message ----- From: "Stewart, Robert" <Robert.Stewart@sig.com> To: <boost@lists.boost.org> 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@sig.com>
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