annotation Deprecated
Overview
def foo(bar, @[Deprecated("Do not try this at home")] baz) end
Deprecations are shown in the API docs and the compiler prints a warning when
using a deprecated feature.
Deprecated types only trigger a warning when they are actually _used_ (e.g.
calling a class method), not when they're just part of type restriction, for
example.
Deprecated parameters only trigger a warning when the particular parameter is
passed in a call. Calls without this parameter are unaffected.