On Wed, Jul 22, 2020 at 6:34 AM Gašper Ažman via Std-Proposals <std-proposals@lists.isocpp.org> wrote:

The *new* version of the wording makes the wording far more clear (could have sworn we sent it in a mailing, but I guess we'll have to send it again):
https://htmlpreview.github.io/?https://raw.githubusercontent.com/BRevzin/cpp_proposals/master/0847_deducing_this/d0847r5.html is the status quo of the paper. There are no design changes or semantic woding changes, just Jens', Barry's and my wording refactors.

The relevant bits:

5b A function parameter declared with an explicit-this-parameter-declaration is an explicit this parameter. An explicit this parameter shall not be a function parameter pack ([temp.variadic]). An object member function is either a non-static member function or a static member function with an explicit this parameter.

Change 12.6.4 [over.sub]/1:

1 A subscripting operator function is a function named operator[] that is a non-static an object member function with exactly one ordinary member parameter.

See, now this I would call a separable bit of the proposal! :)
Do you know if there are any proposals in-flight, or any proposals recently rejected, to get rid of the asymmetries around some of the operators and permit e.g. operator[] and operator() to be free functions?

struct S {
    // Current: operator[] cannot be a non-member function
    friend Element& operator[](S& lhs, int rhs) { return lhs.data_[rhs]; }
};

Or even to permit operators to be static member functions?

struct Comparator {
    // Current: operator() cannot be a static member function
    static bool operator()(int x, int y) const { return x < y; }
};

–Arthur