Tobias Schwinger <tschwinger@neoscientists.org> writes:
I'll continue this discussion (previously in private email) on the boost mailinglist, in order to allow others to join in.
Any critiques (i.e. having a look at the (comparatively small) submission and dropping me a couple of lines) are still very welcome, in fact !
Alexander Nasonov wrote:
[... char array in struct as sizer for type classification via overload resultion ...]
Good point. This will be changed. By the way: the same hack is in the current boost release [boost/type_tratis/function_traits.hpp:177].
This has been changed [ref. 5.3.3].
// tester returns a reference to an array template< /* ... */ > char (& tester( /* ... */ ) ) [size];
This would have been my personal preference. Unfortunately this causes bcc to fail with an 'Internal compiler error'.
Just use an external template template< /* ... */ > typename char_array<size>::type tester( /* ... */ ); (See boost/python/detail/char_array.hpp)
or making it a meta-function
template<std::size_t Size> struct sized_type { typedef char (&type)[Size]; };
and using typename sized_type<Size>::type in place of sized_type<Size>.
This is the current, but not necessarily the best implementation. Comments ?
Whoops! That's basically what I did. If you need to represent zero it has to change slightly.
I believe this could be a common issue - for that matter:
What about a type synthesizer like 'type_with_size<size_t>::type' or a BOOST_TYPE_WITH_SIZE(n)' macro ? Or even: BOOST_SIZED_RESULT_TYPE_OVERLOAD_PROTO(template_args,function_args,size_expression).
Is there something like this in boost somewhere, already ?
See above.
I sure will !
Thanks a lot for your work, ideas and the very nice mail - despite the fact of having no time, that is !
Have you considered wrapping function signature into mpl sequence?
Currently function_signature<T>::type is an mpl::vector and therefore a model of sequence.
Have you seen boost/python/detail/signature.hpp? -- Dave Abrahams Boost Consulting http://www.boost-consulting.com