Hi Giuseppe, std-proposals,

https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2248r7.html

I just noticed today that P2248 "Enabling list-initialization for algorithms" still fails to enable this very common use-case of mine:

    std::vector<int> v = {1,2,3,4,5};

    assert(std::ranges::equal(v, {1,2,3,4,5}));

Was this possibility ever discussed before?

This could be handled by defaulting the `R2` parameter to `initializer_list`, but it probably makes more sense to add a whole new overload of `std::equal`, as follows. (This means it's quite reasonable that P2248 wouldn't have proposed this idea... but I'm still wondering if it's been discussed before.)

In the context of P2248, the answer would be no, it has not been proposed / it's out of scope. P2248's design is to default value-like arguments (e.g. the "value" of std::find) of algorithms using the value type of the range(s) passed as inputs.

What you propose certainly makes lots of sense, we already have some algorithm (e.g. std::(ranges)::max) that supports initializer lists through a dedicated overload, not dissimilar to the code you pasted. One can imagine more examples of same nature (algorithms), as well as extend this to range functionality (e.g. views::zip, views::join_with_view -- etc.) where one would like to simply pass `{a, b, c}`.

It's a bit unfortunate that braced lists are still a weird datatype. They don't deduce template type parameters, they're not views / viewable ranges, etc.; one has to introduce additional overloads or add defaults. I wonder if some codebase has created some tiny range class just to ease the kind of calls that you want to streamline.

Thank you,

-- 
Giuseppe D'Angelo