On Sunday, 18 September 2016 at 15:17:31 UTC, Andrei Alexandrescu
There are quite a few situations in rdmd and dmd generally when
we compute a dependency structure over sets of files. Based on
that, we write new files that overwrite old, obsoleted files.
Those changes in turn trigger other dependencies to go stale so
more building is done etc.
If so we need it in druntime.
Introducing phobos into ddmd is still considered a nono.
Personally I am pretty torn, without range-specific optimizations
in dmd they do incur more overhead then they should.