xpidl currently supports nsAString as a scriptable data type, but it does not support nsACString as a scriptable data type. i scratched my head, and couldn't come up with a reason for why this might be the case. if we can support nsAString, then it seems like we should also be able to support nsACString.
nsACString's as parameters would be particularly useful to necko, which currently deals primarily with |char| arrays and as a result is forced to malloc'ate all string out parameters (in order to maintain scriptable interfaces). it would be really nice and likely improve performance in a significant way if necko could instead simply write to a nsACString. so, i'm wondering... what is keeping xpidl from providing a nsACString data type? darin
