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Subject: Re: [boost] [date_time] [#1861] Change for the default duration format
From: Stewart, Robert (Robert.Stewart_at_[hidden])
Date: 2009-06-01 11:55:04

Andrey Semashev wrote
On Sunday, May 31, 2009 8:32 AM
> There's a Boost.DateTime ticket:
> The initial problem was that the default handling of the %H
> format specifier (passing it to strftime) played badly with
> time durations that could be longer than 24 hours. The
> resolution was to provide additional %O format specifier
> that does not have 24 hour restriction.

I suspect that's not common -- other than for the OP, perhaps. Jeff's explanation in the associated list message implies that, too.

> However the original poster proposes to change the default
> format of time durations from %H:%M:%S%F to %O:%M:%S%F so
> that formatted durations are always allowed to be longer
> than 24 hours. I mostly agree with this change, however it
> is clearly a breaking change that can affect error checking
> in some cases.

Changing the default will create surprises in some cases. I'd prefer to see error checking -- an exception when the valid %H range is violated. That would alert library users to the problem when violated and the exception message could even suggest the need for %O (as should the docs, of course).

That would provide useful behavior for those violating the range unknowingly and it would avoid breaking compatibility and, reasonable expectations for users.

Rob Stewart robert.stewart_at_[hidden]
Software Engineer, Core Software using std::disclaimer;
Susquehanna International Group, LLP

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