C++ UFCS update

[krzaq via Digitalmars-d]

On Tuesday, 16 February 2016 at 07:59:49 UTC, w0rp wrote:
> Personally, I find this proposal for C++ to be laughable. It's 
> like hitch hiking from New York to California, and only getting 
> as far as Texas and calling it good.
>
> The great thing about our UFCS is the left-to-right chaining of 
> algorithms.
>
> x.map!(...).filter!(...).reduce!(...)
>
> It beats the Hell out of...
>
> reduce!(...)(filter!(...)(map!(...)(x)))
>
> This proposal will encourage non member functions, which is 
> good, but will never reach the "aha" moment D had which gave us 
> UFCS chaining.

I agree completely. Form my point of view, UFCS is D's biggest 
advantage over C++ (beating CTFE and saner templates). It was the 
thing that I hoped for the most in C++17. Alas, we'll be forced 
to write onion code. This sucks.

By the way, your example in C++ would be even worse:

auto sum_of_filtered = x
     .map([&](auto&& val){ foo(val); })
     .filter([](auto&& val){ return is_bar(val); })
     .reduce(std::plus<>{});

vs

auto sum_of_filtered =
reduce(filter(map(x, [&](auto&& val){ foo(val); }) ,[](auto&& 
val){ return is_bar(val); }), std::plus<>{});

Try adding an additional pass there. Where do you put the comma 
and second/third argument?

I have no idea how to indent that properly and creating a myriad 
of named temporary variables for no valid reason makes me hurt 
inside.