[cairo] Cairo and ISO C++

[Herb Sutter]

Thanks Behdad,

> During cairo's development, there were some decisions made that we
> regretted later on.  I was going to suggest that those be revisited for
> standardization, but reading the documents you linked, I think that will go
> down the same design-by-committee path that you are trying to avoid.

It sounds like those would be good to know about regardless, if you could share.

Actually we mainly want to avoid that for the initial proposal, but if there are known 'errata' that would be good to know about. Possibly they could be addressed in the C++ wrapping, if they can be addressed without changing Cairo. Alternatively, perhaps this would be a good point to consider addressing some of them in Cairo as well if you think that's proper, given that if this standardization process bears fruit the audience of the Cairo API will expand to a lot of new users. In any event I think it would be good to know about them.

> So, personally, I fully support the current position outlined in the N3825
> document and am willing to help with the effort.

That's great. The best contact person right now would be Michael McLaughlin, cc'd hereto, who is actively working on the actual proposal.

> I sure would love to see cairo's functionality and quality be available
> anywhere C++ is :).

Us too! Again, just to set expectations, at this point it's just a proposal that has not yet been seen by the committee. We'll know more about its potential support after feedback from the February standards meeting. But we wanted to be sure we ran this by you guys up front to get direction and avoid surprises.

Thanks,

Herb


> -----Original Message-----
> From: Behdad Esfahbod [mailto:behdad.esfahbod at gmail.com] On Behalf Of
> Behdad Esfahbod
> Sent: Wednesday, January 1, 2014 1:57 AM
> To: Herb Sutter; cairo at cairographics.org
> Cc: 'Chris Wilson'; 'Michael McLaughlin'; 'jason zink'
> Subject: Re: Cairo and ISO C++
> 
> On 14-01-01 10:23 AM, Herb Sutter wrote:
> > Hi, my name is Herb Sutter and I chair the ISO C++ standards
> > committee. Behdad referred me to this list as the right place to raise this
> question:
> >
> > We are actively looking at the potential standardization of a basic 2D
> > drawing library for ISO C++, and would like to base it on (or outright
> > adopt, possibly as a binding) solid prior art in the form of an
> > existing library. You can find a quick summary of goals and discussions to
> date in these two papers:
> >
> > ·         http://isocpp.org/files/papers/n3791.html
> >
> > ·         http://isocpp.org/files/papers/N3825.pdf
> >
> > As noted in the latter paper, we are currently investigating the
> > direction of proposing a mechanically C++-ified version of Cairo.
> > Specifically, “mechanically C++-ified” means taking Cairo as-is and
> > transforming it with a one-page list of mechanical changes such as
> > turning _create functions into constructors, (mystruct*, int length)
> > function parameters to vector<struct>& parameters, that sort of thing
> > – the design and abstractions and functions are unchanged. This would
> > also allow us to track Cairo as it evolves in the future, by continuing to
> reapply the same rules to new updates to Cairo.
> 
> Very interesting!  Looks like you already got most of it written down.  I think
> cairo is indeed a great fit for what the group is looking for.
> 
> During cairo's development, there were some decisions made that we
> regretted later on.  I was going to suggest that those be revisited for
> standardization, but reading the documents you linked, I think that will go
> down the same design-by-committee path that you are trying to avoid.  So,
> personally, I fully support the current position outlined in the N3825
> document and am willing to help with the effort.
> 
> 
> > We know about Cairomm but it seems to have languished so we are
> > focused on current Cairo as a starting point, even though it’s not C++
> > -- we believe Cairo itself it is very well written C (already in an OO
> > style, already const-correct, etc.).
> 
> Yes, I think you can go straight to cairo itself.  I'm guessing that you should be
> able to autogenerate the binding.  Perhaps, using gobject-introspection to
> generate a typelib for cairo, then reading the typelib, transforming it, and
> writing out the binding.
> 
> 
> > We want to make sure we’re doing this in the right way and with the
> > group’s approval, so your feedback would be much appreciated. Also, we
> > might want to reuse parts of the Cairo documentation in our
> > specification, which we understand is governed by MPL 1.1, and we
> > would like to know if this would be all right with your group.
> 
> I sure would love to see cairo's functionality and quality be available
> anywhere C++ is :).
> 
> Cheers,
> --
> behdad
> http://behdad.org/