I certainly consider iconv as one possible implementation of
Decode and a future
A goal of the current design is to allow largely non-copying decoders when the source encoding is a subset of UTF-8, such as UTF-8 itself or ASCII. In these cases, the decoder’s job is to validate the byte stream; but to consume a buffered reader without extra allocations, occasionally a partial UTF-8 sequence needs to be saved in the decoder state to assemble the complete UTF-8 sequence across adjacent buffered reads.
The code currently in master is already outdated; bear with me while I’m sitting on some pending changes, which need some borrow checker issues to be resolved.