Re: [PATCH] Reimplement __gnu_cxx::__ops operators

["François Dumont" <frs.dumont@gmail.com>]

On 07/12/2023 14:41, Jonathan Wakely wrote:
> On Wed, 6 Dec 2023 at 20:55, François Dumont <frs.dumont@gmail.com> wrote:
>> I think I still got no feedback about this cleanup proposal.
> Can you remind me why we have all those different functions in
> predefined_ops.h in the first place? I think it was to avoid having
> two versions of every algorithm, one that does *l < *r and one that
> does pred(*l, *r), right?
Yes, that was the purpose.
>
> One property of the current code is that _Iter_less_iter will compare
> exactly *lhs < *rhs and so works even with this type, where its
> operator< only accepts non-const arguments:
>
> struct X { bool operator<(X&); };
>
> Doesn't your simplification break that, because the _Less function
> only accepts const references now?

Indeed, I thought more about the problem of const qualification on the 
operator(). This is why _Comp_val is mimicking what _Not_fn does.

To be honnest I even thought that this kind of operator above was more a 
user code issue than a real use case we need to handle. But it looks 
like you, I guess the C++ Standard then, impose to support it.

I'll rework it then, thanks for the proposal below and in your other email.