Awkwardness with std::fmt::Display? about tabwriter HOT 2 OPEN

Regrettably, I don't see a clean answer here with the current API. The fundamental problem is that a TabWriter is coupled to io::Write---which supports arbitrary bytes---where as the Display infrastructure is a "purer" world that only supports UTF-8.

I guess the ideal API here would permit one to create a TabWriter that wraps a std::fmt::Write instead of a std::io::Write. Then I think you'd just need to do let f = TabWriter::new(f); and then things would be pretty natural from there.

The problem is that TabWriter as it exists today is wedded to std::io::Write.

Probably the right way to do this is to create a TabWriterBuilder that has from_io and from_fmt constructors. They would both produce a TabWriter<W>, but the former would have W: io::Write where as the latter would have W: fmt::Write. The TabWriter would then implement io::Write and fmt::Write itself as appropriate.

Unfortunately, that feels like a "tabwriter 2" kind of thing to me. I personally doubt I'll do that unless I run into the same use case as you. :-)

from tabwriter.

Thanks much for looking at this, and for the clear explanation. Mostly just wanted to make sure I wasn't missing something obvious.

from tabwriter.