From: Edward Diener (eldiener_at_[hidden])
Date: 2021-01-25 21:53:58
On 1/25/2021 4:36 PM, Niall Douglas via Boost wrote:
> On 25/01/2021 20:44, Edward Diener via Boost wrote:
>
>> I offer all this up as a possibly valid reason why testing a Boost
>> library on some other platform/architecture, other than the usual
>> Intel x64 on Mac/Linux/Windows, is not going to be a big priority for
>> any Boost library developer/maintainer.
>
> I would take the view that over half of all computing devices where C++
> is likely to run are ARM or AArch64.
>
> Therefore one ought to be targeting one's code at those preferentially
> to other architectures.
>
> You're right that for high level libraries, C++ is generally very
> portable. But for low level libraries, and any high level libraries
> which depend on those low level libraries, there can be some _very_
> nasty surprises e.g. ARM does not implement all of IEEE 754, and ARM is
> strict about use of acquire-release atomics as well as alignment in a
> way x64 is not.
>
> Therefore, in my opinion, if your code works well on ARM, it's very
> likely to work on x64. But the reverse is not true.
Please name the Boost low level libraries which have specific code aimed
at the platform/architecture combination. I am not talking about code
for just Mac or Linux or Solaris or Windows but code that actually does
something different when run on Intel or ARM or AArch64 etc. I still
imagine that if such Boost libraries exist there are still very, very
few Boost libraries with dependence on such code. I am not arguing that
testing on non-Intel is in any way wrong but simply that very, very few
libraries should be impacted by different architectures in any way.