[C++-sig] Re: indexing_v2 status update

[Raoul Gough]

David Abrahams <dave at boost-consulting.com> writes:

> Raoul Gough <RaoulGough at yahoo.co.uk> writes:

[snip]
>> Does mpl::set currently work? I seem to remember that you
>> suggested using mpl::vector at the moment, which raised some doubt
>> about this.
>
> see libs/mpl/test/set.cpp.  You can try it yourself and find out.

I've looked at the test cases, which I *think* I understand after
looking at the preprocessor output. From what I can see, there are
tests for empty and one-element sets only. If that really is the case,
I don't find it very convincing. I'm tending towards the bitflag
approach at the moment anyway.

By the way, I've been wondering about what the container suite
interface should look like after moving to feature sets instead of
static boolean constants. I'm thinking along these lines:

template<
     class Container,
     SOME_KIND_OF_SET features = supported_features<Container>,
     class Algorithms = algorithms<Container>
> container_suite;

where supported_features does the traits-like work of figuring out
what the container can support. This would allow client code to
override the features explicitly if something is not needed.
Curiously, I think the Algorithms implementation doesn't need to know
this information itself, since it is up to the container_suite to
decide what Algorithms functions to instantiate.

Another option would be to determine the supported features within the
existing container_traits framework, and provide an optional
features_to_disable parameter to the container_suite. Any thoughts or
preferences on this front?

-- 
Raoul Gough.
export LESS='-X'