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Re: Increase size of std::function small object buffer
- From: Jonathan Wakely <jwakely dot gcc at gmail dot com>
- To: Oleg Endo <oleg dot endo at t-online dot de>
- Cc: Felix Winterhalter <felix at audiofair dot de>, "libstdc++" <libstdc++ at gcc dot gnu dot org>
- Date: Sun, 31 Jul 2016 11:47:19 +0100
- Subject: Re: Increase size of std::function small object buffer
- Authentication-results: sourceware.org; auth=none
- References: <91cb14bf-1d7a-aefd-e6bc-e49a2275ddb8@audiofair.de> <CAH6eHdQsoZ4rE--K6NFVXaJSDPqp4jyqR=N9mv1_Efpccozt4A@mail.gmail.com> <1469921973.2632.260.camel@t-online.de>
On Jul 31, 2016 12:39 AM, "Oleg Endo" wrote:
>
> On Sat, 2016-07-30 at 22:07 +0100, Jonathan Wakely wrote:
>
> >
> > > I see a simple solution to this:
> > >
> > > Increase the internal buffer of std::function to 24 bytes from 16
> > > bytes
> > > as the method pointer uses 16 bytes while the pointer to class
> > > instance
> > > uses another 8 bytes.
> >
> > That would break the library ABI, so is not an option.
> >
>
> He was saying that he's on an embedded system. Very often ABI
> stability is not of a concern in such cases. Of course on
> desktop/server systems ABI stability is a concern. But imposing it on
> every system?
Then the sources could be changed locally. It would be a one line change.
> Maybe we could have some configure options to control these kind of
> parameters when building the toolchain?
See https://gcc.gnu.org/ml/libstdc++/2016-05/msg00073.html
Of course it would be welcome if the people who want such things were
to help. I don't need it and my employers don't need it (but I know
people who have expressed interest in using it).