[swift-users] KeyedDecodingContainerProtocol decode methods non-mutating?

[Ingo Maier]

Can anybody tell why the decode methods in UnkeyedDecodingContainer
are marked mutating but those in KeyedDecodingContainerProtocol and
SingleValueDecodingContainer are not? Is it a simple oversight or is
there a reason for this? It seems to me that all of them should be
mutating.

Thanks,
Ingo