Of the ones in P2214 tier 1:

chunk, slide, and join_with are sometimes not const-iterable.
chunk_by is never const-iterable.

On Fri, Nov 5, 2021 at 6:38 AM Nicolai Josuttis via Lib-Ext
<lib-ext_at_[hidden]> wrote:
>
> Hi,
>
> IIUC, the following C++20 views can't be used when const because you can
> only iterate over element when being not const:
>
> Always:
> filter_view
> drop_while_view
> split_view
> Sometimes:
> drop_view
> reverse_view
> join_view
>
> Now as we seem to get a lot of new views for C++23,
> could somebody tell me about the state of iterating over all these views
> when they are const?
>
> I ask, because I have to make a very important decision now for all of
> my trainings:
> I have to decide when to introduce universal/forwarding references now
> to ordinary programmers, because ranges/views made them first-class
> language features.
> In fact, I wonder whether I shouldn't even start with
> universal/forwarding references as THE reference now (teaching it
> earlier than const auto&).
>
> --
> Nicolai M. Josuttis
> www.josuttis.de
>
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