This is the derive support for #3774 (see also #3775, #3777)
This combined with `value_parser` replaces `parser`. The main
frustration with this is that `ArgAction::Count` (the replacement for
`parse(from_occurrences)` must be a `u64`. We could come up with a
magic attribute that is meant to be the value parser's parsed type. We
could then use `TryFrom` to convert the parsed type to the user's type
to allow more. That is an exercise for the future. Alternatively, we
have #3792.
Prep for this included
- #3782
- #3783
- #3786
- #3789
- #3793
This is part of the `App` rename.
Previously, I was concerned about not being able to deprecate
For backwards compatibility, we still expose the `IntoApp` name.
No good solution for transitioning the trate name, unfortnately, since
we can't mark `use`s as deprecated (we can, it just does nothing).
I got rid of the `into` prefix because that implies a `self` parameter
that doesn't exist.
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
