https://issues.dlang.org/show_bug.cgi?id=2954
--- Comment #16 from [email protected] --- Niche or not, this problem ought to be fixed. It's been how long now, and we still haven't gotten our act together on AA's. Lookups should be permissive and allow types that are comparable with the key type (e.g., using a char[] to lookup a T[string] should be fine). Assignment, however, must be much stricter because of aliasing issues; it should only allow types implicitly convertible to the key type (it's illegal to assign a char[] key to T[string], because if the key is subsequently modified via the mutable reference, the AA breaks.) --
