Implicit cast to const of result returned from findSplit()

[Per Nordlöw]

On Monday, 5 November 2018 at 13:26:18 UTC, Per Nordlöw wrote:
> AFAICT, it looks like a missing bool qualifier on 
> `opCast!bool`, right?

Fixed at

https://github.com/dlang/phobos/pull/6749