When an Arg uses .min_values(0), that arg's value(s) are effectively
optional. This is conventionaly denoted in help messages by wrapping the
arg's values in square brackets. For example:
--foo[=value]
--bar [value]
This kind of argument can be seen in the wild in many git commands; e.g.
git-status(1).
Signed-off-by: Peter Grayson <pete@jpgrayson.net>
The error was when doing `#[clap(arg_enum, default_value_t = ...)]`.
Good example of why we should minimize `use`, at least in tests
(besides reducing merge conflicts, code churn, etc).
While I'm unsure how much type specialization we should do, we
intentionally have the `arg_enum` attribute for doing special behavior
based on it, so let's take advantage of it.
Fixes#3185
The extra whitespace was targeted at machine processing for a subset of
users for a subset of runs of CLIs. On the other hand, there is a lot
of concern over the extra verbose output.
A user can set the help template for man, if desired. They can even do
something (env? feature flag?) to make it only run when doing man
generation. We also have #3174 in the works.
So let's focus on the end-user reading `--help`. People wanting to use
`help2man` have workarounds to do what they need.
Fixes#3096
The main care about is that when we override a `flatten` / `subcommand`
doc comment in a parent container, that we make sure we take nothing
from the child container, rather than implicitly taking one `about` ut
not `long_about`.
To do this, and to play the most safe with long help detection, we reset
`long_about` to default when there is no doc comment body to use for
`long_about`.
Fixes#2983
Adding in a `StructOpt` derive with `structopt` attributes, with
deprecation notices. Unofrtunately, not as many deprecation warnings as
I would like. Apparently, you can't do them for a `use` of a derive? I
also wanted to inject code that would trigger a deprecation notice for
attributes but that would require enough of a refactor that I didn't
consider it worth it. We are at least providing a transition window
even if it means we'll have to remvoe it next major release without a
deprecation warning.
