Recommendations on avoiding range pipeline type hell

[SealabJaster]

On Sunday, 16 May 2021 at 12:54:19 UTC, Chris Piker wrote:
> ...

If all you need is a single type for the parameter(s) and return 
type, then it can be simplified a bit to save you some typing:

```d
struct S(T)
{
    alias FT = T function(T);
    FT func;
}

void main()
{
     auto a = S!int(a => a*2);
     auto b = S!int(a => a+2);
     a = b;
}
```