On 03/17/2017 03:06 PM, Peter Dimov via Boost wrote:
A few comments... Most algorithms take the typelist as the first argument, but others do not, e.g. mp_transform<F, L...>. If possible, I would like to see all algorithms take typelist as the first argument. It looks like the current order is dictated by the requirements of mp_tranform_impl. Would it be possible to swap the types where the algorithm is declared? For example: template<class L, template<class...> class F> using mp_transform = typename detail::mp_transform_impl<F, L>::type; Apropos mp_transform, would it be possible to extend it such that we can pass a type-trait directly to it? For example: using const_list = mp_transform<std::add_const, typelist>; instead of using std::add_const_t. The reason I ask is that I have lots of my own domain-specific type-traits that does not come with a _t version, so this is mainly for convenience. The reference documentation is a bit terse and obscure. For example, the documentation for mp_find tells us in a convoluted way that it returns the index of a type in a typelist. It could also mention that it is the dual algorithm to mp_at, which returns a type at an index in a typelist.