These are chat archives for boostorg/hana

29th
Jun 2017
Louis Dionne
@ldionne
Jun 29 2017 01:15
@shreyans800755 Hey, sorry, I didn’t open my Gitter for several weeks. I would say the highest paying feature right now is definitely boostorg/hana#301.
This is going to be huge, but I’m stuggling to setup time for it.
Another thing that would be useful is to add a concept for those set theoretic operations.
Otherwise, lots of issues are either documentation-related, performance-related, or quite tricky metaprogramming/generic programming problems (e.g. the trivially-constructible pair stuff). Not sure how much that interests you, but if so you can pick anything you’d like.
Barrett Adair
@badair
Jun 29 2017 01:20
Nice work on index_if. That's a real goodie. I've written my own non-generic version of that many times
Louis Dionne
@ldionne
Jun 29 2017 01:23
It’s all @ricejasonf !
Btw, I think what this points out is the fact that iterators are indeed useful for some use cases.
Jason Rice
@ricejasonf
Jun 29 2017 01:28
thanks :D
Jason Rice
@ricejasonf
Jun 29 2017 04:53
Perhaps if the views used reference_wrappers they could be const
I'm guessing they are non const references right now to prevent temporaries. Is that the reason?
Louis Dionne
@ldionne
Jun 29 2017 06:09
I’m not sure I understand what you mean, but IIUC they are references just because we might want to have either a “reference to const” or a “reference to non-const” container.
We may want to modify the elements of the container or we might not, for example.
Also, they’re only held by reference when they’re a container, cause views are held by value.
Jason Rice
@ricejasonf
Jun 29 2017 06:25
Ah. I guess I should play around with it before a I start asking questions.
Louis Dionne
@ldionne
Jun 29 2017 06:37
No, not at all!
I mean, do play with it by any means, but don’t wait to ask questions
Shreyans
@shreyans800755
Jun 29 2017 17:43

@ldionne I'll try look at the PR and see if it interests me.

Another thing that would be useful is to add a concept for those set theoretic operations.

Wouldn't this require latest gcc7.x (with c++17 support, basically) ? And what about the backward compatibility ?

Jason Rice
@ricejasonf
Jun 29 2017 17:45
Hana has its own method for simulating concepts which are basically traits
Shreyans
@shreyans800755
Jun 29 2017 17:46
Oh okay.
Jason Rice
@ricejasonf
Jun 29 2017 17:48
Shreyans
@shreyans800755
Jun 29 2017 18:00
:smiley:
Looks like a big video, will have a look as time permits
Jason Rice
@ricejasonf
Jun 29 2017 19:07
at 11:07 it goes over hana concepts