D-like ranges for C++17 in a 2.5 klines single header file

[user1234]

On Tuesday, 13 October 2020 at 09:12:58 UTC, Per Nordlöw wrote:
> Here's a more compact encoding of D/C++20-like ranges packed 
> into a 2.5 klines single header file:
>
> The file `ranges.hpp` syntaxcheck in 0.3s with Clang 10 on 
> Ubuntu 20.04 on my 6 year old laptop.
>
> https://github.com/simonask/rx-ranges/

compared to std.range or std.algorithm it is very unpleasant to 
read.