On Thu, Feb 15, 2018 at 4:00 PM, Peter Dimov via Boost < boost@lists.boost.org> wrote:
Zach Laine wrote:
(std::tuple is a *lot* slower to compile than hana::tuple)
Is it? Interesting.
Either way, that's up to the user, isn't it? If he wants to use std::tuple and index with `get(expr, mp_int<0>())` or `get_c<0>(expr)` instead of `get(expr, 0_c)`, let him.
It could be, but that would be a much more complicated interface. As it is, the user need only specify an expression kind non-type template parameter and a Hana tuple to create a model of Expression. Adding another point of customization by allowing her to specify anything for the tuple that models some Tuple concept is a lot to add, considering how simple the status quo is. I think it should be hana::tuple or std::tuple rather than any Tuple. Zach