Due to macro expansions, a `syn` type may be wrapped in multiple
'layers' of `syn::Type::Group`. However, `clap_derive` currently does
not check for `syn::Type::Group`, which will cause an `Option` (along
with other matched types) to fail to be detected when it results from a
macro expansion.
This commit 'unwraps' outer type groups before checking the
user-provided types against well-known types. Currently, these groups
may not be present due to a rustc bug (rust-lang/rust#43081)
However, once https://github.com/rust-lang/rust/pull/73084 is merged,
these groups will be present in more cases. This commit makes `clap`
compatible with both older and newer versions of rustc.
This PR switches the Arg::Short macro to take a character instead of a string. It removes the hacky code in the Method to_token method and implements the logic for Short when parsing the clap derive arguments.
Fixes#1815.
1681: WIP: Extract subcommands into separate trait r=pksunkara a=CreepySkeleton
Not-yet-working-but-almost-there "multiple traits" approach. More or less done, what's left is to catch some bugs and adapt tests/examples.
For the record: it took so long because of RL stuff (who would have thought?) and because [there was a detailed description of the experience I've had here, but it was deleted because it contained a lot of profanity and emotional notes].
As the only person alive that understands how the derive works (if you won't blow your own horn, nobody will do it for you, yeah), I'd like to made a statement: we Do need the refactoring.
Co-authored-by: CreepySkeleton <creepy-skeleton@yandex.ru>
