Re: Thoughts on Variant creation

[José Alburquerque <jaalburquerque gmail com>]

On Friday, December 28, 2012, José Alburquerque  wrote:
> On Sat, 2012-12-22 at 13:47 -0800, Andrew Potter wrote:
> > I've been thinking about how we create variants in glibmm and why its
> > more of a pain than in C. The common case ultimate goal of variants is
> > to throw a data structure into a tuple. In C, you can use
> > g_variant_new() and a format string, and hand it pointers to your hard
> > data. 1 method returns the desired result if you don't need to build a
> > container variant.
> >
> >
> > However, currently in glibmm you have to call a ::create() method for
> > each individual data element before you can call create_tuple(). It is
> > relatively cumbersome for nontrivial tuples.
> >
> >
> > There are a lot of possible solutions, but I have no idea which is the
> > best. We could make a really bare wrapper g_variant_new() that passes
> > all the arguments through and just Glib::wrap()s the result into a
> > Glib::VariantContainerBase. Or, we could parse the format string
> > ourselves and call the appropriate ::create() methods.
> >
> >
> > Maybe we could break ground with a C++11 std::tuple constructor. It'd
> > be really, really nice if you could just:
> >
> >
> > auto vtuple = VariantContainerBase::create_tuple({(int) item1, (float)
> > item2, (std::map) item3});
> >
> >
> > Thoughts?
>
> One possible solution might be to have a temporary limited tuple class
> in glibmm along with a Glib::Variant<> class for it until c++-11 is
> widely available.  I'm not sure what that would involve.

Another possible temporary solution might be to add one or more templated methods with arguments of different possible types to Glib::VariantContainerBase to create the tuples.

--

José