When upgrading our company projects from clap 3.1 to clap 3.2 I had
to fix several references to `clap::lazy_init`. People are not
supposed to do that, but that's hard to enforce.
Hope placing `once_cell` reexport into `__macro_refs` prevent at
least some of the such issues in the future.
This adds a new `Cargo.toml` feature named `deprecated` that opts
controls whether deprecation warnings show up. This is starting off as
non-default though that may change (see below).
Benefits
- Allows a staged rollout so a smaller subset of users see new
deprecations and can report their experience with them before everyone
sees them. For example, this reduces the number of people who have to
deal with #3822.
- This allows people to defer responding to each new batch of
deprecations and instead do it at once. This means we should
reconsider #3616.
The one risk is people who don't follow blog posts and guides having a
harder time upgrading to the next breaking release without the warnings
on by default. For these users, we reserve the right to make the
`deprecated` feature `default`. This is most likely to happen in a
minor release that is released in conjunction with the next major
release (e.g. when releasing 4.0.0, we release a 3.3.0 that enables
deprecations by default). By using a feature, users can still disable
this if they want.
Thanks @joshtriplett for the idea
Putting it on the doc comment is weird. We are now putting it on the
field which is a slight improvement. This better conveys "this is
auto-generated".
No test was added because the use case that I know of for exposing this
is short lived.
We aren't enumerating arguments but values for an argument, so the name
should reflect that.
This will be important as part of #1807 when we have more specific
attribute names.
This is mostly about avoiding criterion's build times when just
developing clap itself.
I'm assuming the derive test changed because criterion's clap v2 isn't
in the dependency tree anymore.
This will make it easier to divide off parser logic for adding in
actions.
This does mean we can't provide error reporting on bad values with
`bool` but
- We should have also been doing that for `from_flag`
- We'll be dropping this soon in clap4 anyways
For clap 3, its opt-in as a precaution against breaking
compatibility in some weird cases.
This does require the types to implement `Clone`.
Fixes#3734Fixes#3496Fixes#3589
