Ah. If that's the case, as you point out people might have already been using a leading underscore (although they shouldn't for idiomatic reasons), leading to a

Ah. If that's the case, as you point out people might have already been using a leading underscore (although they shouldn't for idiomatic reasons), leading to ambiguity around 2015 code: fn async(enabled: bool) {} fn _async(enabled: bool) {} 2018 code calling that: _async(true); // Which is this calling?