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Re: [patch] Default to --enable-libstdcxx-time=auto


On 22 May 2013 12:49, Jonathan Wakely wrote:
> On 22 May 2013 12:15, Jakub Jelinek wrote:
>>
>> If now() can be perhaps with worse precision emulated in configurations not
>> built against glibc 2.17, perhaps best solution would be to
>> add now()@@GLIBCXX_3.4.18 into 4.8.1 (and change all 3.4.18 symbols to
>> 3.4.19) and have now()@GLIBCXX_3.4.17 (note, just one @) as compatibility
>> alias to that.
>
> The problem for steady_clock::now() isn't one of precision, it's that
> it isn't steady if we don't use the monotonic clock.  We could define
> a non-steady steady_clock (with the same precision as system_clock)
> but is that helpful to users?  If that's what we want then yes, we can
> do the symbol versioning you suggest.

In fact we were already providing a non-steady steady_clock in the
default configuration, we just define it as a typedef for
system_clock, so we can export steady_clock::now() as an alias for
system_clock::now() when the two clocks are the same type.  When
they're not the same type there will be a real symbol present in the
.so


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