`in` no longer same as `const ref`

[Nordlöw via Digitalmars-d]

On Sunday, 29 January 2017 at 11:49:19 UTC, Nordlöw wrote:
> https://github.com/dlang/druntime/pull/1748/files
>
> Why is `in` no longer the same as `const ref`?

Correction:

Why is `in` no longer the same as `const scope`?