AMDG Tobias Schwinger wrote:

Actually,

function_type< int(...), tag<components<int(...)>, stdcall_cc>

...

::type

is equivalent and doesn't read too bad, does it?

I was concerned more about the duplication of int(...). here is a contrived example. template<class M, class V, class I> struct get_function : function_type< typename mpl::at<M, typename mpl::at<V, I>::type>::type, tag< components< typename mpl::at<M, typename mpl::at<V, I>::type>::type >, default_cc

{};

Of course a simple template could fix this: template<class F, class Tag> struct mutate_function : function_type<F, tag<mpl::if_<is_callable_builtin<F>, components<F>, F>::type, Tag> > {};

...

...

...

How often are the cv tags likely to be used? They are redundant since for member functions this information is already available in the first parameter. If they are not a very common thing to need, I would propose simply removing them from the interface.

It might not be wise to throw out that feature. Currently cv-qualified function types are illegal, but it is likely they will be allowed in some contexts in the future (there is a defect report on that part of the standard).

shouldn't that be handled by add_const/is_const?

Further, these tags might come handy to work around BCC deficiencies. I hope that would be an implementation detail.

In Christ, Steven Watanabe