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transition: derive_more 0.99.17 → 1.0.0

derive_more has one more release (0.99.18) unpackaged on the 0.99 branch until a semver-incompatible bump to 1.0.0.

Upstream changelog says:

## 1.0.0 - 2024-08-07

More than 8 years after the first commit and almost 5 years after the 0.99.0
release, `derive_more` has finally reached its 1.0.0 release. This release
contains a lot of changes (including some breaking ones) to make it easier to
use the derives and make it possible to extend them without having to break
backwards compatibility again. There are five major changes that I would like
to call out, but there are many more changes that are documented below:
1. There is a new `Debug` derive that can be used to easily customize `Debug`
   formatting.
2. A greatly improved `Display` derive, which allows you to do anything that
   [`thiserror`](https://github.com/dtolnay/thiserror) provides, but it works
   for any type not just errors. And by combining the `Display` derive with the
   `Error` and `From` derives, there shouldn't really be any need to use
   `thiserror` anymore (if you are missing a feature/behaviour from `thiserror`
   please report an issue).
3. Traits that can return errors now return a type that implements `Error`
   when an error occurs instead of a `&'static str`.
4. When using `use derive_more::SomeTrait` the actual trait is also imported
   not just the derive macro. This is especially useful for `Error` and
   `Display`
5. The docs are now rendered on docs.rs and are much better overall.


### Breaking changes

- The minimum supported Rust version (MSRV) is now Rust 1.75.
- Add the `std` feature which should be disabled in `no_std` environments.
- All Cargo features, except `std`, are now disabled by default. The `full`
  feature can be used to get the old behavior of supporting all possible
  derives.
- The `TryFrom`, `Add`, `Sub`, `BitAnd`, `BitOr`, `BitXor`, `Not` and `Neg`
  derives now return a dedicated error type instead of a `&'static str` on
  error.
- The `FromStr` derive now uses a dedicated `FromStrError` error type instead
  of generating unique one each time.
- The `Display` derive (and other `fmt`-like ones) now uses
  `#[display("...", (<expr>),*)]` syntax instead of
  `#[display(fmt = "...", ("<expr>"),*)]`, and `#[display(bound(<bound>))]`
  instead of `#[display(bound = "<bound>")]`. So without the double quotes
  around the expressions and bounds.
- The `Debug` and `Display` derives (and other `fmt`-like ones) now transparently
  delegate to the inner type when `#[display("...", (<expr>),*)]` attribute is
  trivially substitutable with a transparent call.
  ([#322](https://github.com/JelteF/derive_more/pull/322))
- The `DebugCustom` derive is renamed to just `Debug` (gated now under a separate
  `debug` feature), and its semantics were changed to be a superset of `std` variant
  of `Debug`.
- The `From` derive doesn't derive `From<()>` for enum variants without any
  fields anymore. This feature was removed because it was considered useless in
  practice.
- The `From` derive now uses `#[from(<types>)]` instead of `#[from(types(<types>))]`
  and ignores field type itself.
- The `Into` derive now uses `#[into(<types>)]` instead of `#[into(types(<types>))]`
  and ignores field type itself.
- The `Into` derive now generates separate impls for each field whenever the `#[into(...)]`
  attribute is applied to it. ([#291](https://github.com/JelteF/derive_more/pull/291))
- Importing a derive macro now also imports its corresponding trait.
- The `Error` derive is updated with changes to the `error_generic_member_access`
  unstable feature for nightly users. ([#200](https://github.com/JelteF/derive_more/pull/200),
  [#294](https://github.com/JelteF/derive_more/pull/294))
- The `as_mut` feature is removed, and the `AsMut` derive is now gated by the
  `as_ref` feature. ([#295](https://github.com/JelteF/derive_more/pull/295))
- A top level `#[display("...")]` attribute on an enum now requires the usage
  of `{_variant}` to include the variant instead of including it at `{}`. The
  reason is that `{}` now references the first argument to the format string,
  just like in all other format strings. ([#377](https://github.com/JelteF/derive_more/pull/377))

### Added

- Add support captured identifiers in `Display` derives. So now you can use:
  `#[display(fmt = "Prefix: {field}")]` instead of needing to use
  `#[display(fmt = "Prefix: {}", field)]`
- Add `FromStr` derive support for enums that contain variants without fields.
  If you pass the name of the variant to `from_str` it will create the matching
  variant.
- Add `#[unwrap(owned, ref, ref_mut)]` attribute for the `Unwrap` derive.
  By using them, it is possible to derive implementations for the reference types as well.
  ([#206](https://github.com/JelteF/derive_more/pull/206))
- Add `TryUnwrap` derive similar to the `Unwrap` derive. This one returns a `Result` and does not panic.
  ([#206](https://github.com/JelteF/derive_more/pull/206))
- Add support for container format in `Debug` derive with the same syntax as `Display` derives.
  ([#279](https://github.com/JelteF/derive_more/pull/279))
- `derive_more::derive` module exporting only macros, without traits.
  ([#290](https://github.com/JelteF/derive_more/pull/290))
- Add support for specifying concrete types to `AsRef`/`AsMut` derives.
  ([#298](https://github.com/JelteF/derive_more/pull/298))
- Add `TryFrom` derive for enums to convert from their discriminant.
  ([#300](https://github.com/JelteF/derive_more/pull/300))
- `#[inline]` attributes to `IsVariant` and `Debug` implementations.
  ([#334](https://github.com/JelteF/derive_more/pull/334)
- Add `#[track_caller]` to `Add`, `Mul`, `AddAssign` and `MulAssign` derives
  ([#378](https://github.com/JelteF/derive_more/pull/378)


### Changed

- The `Constructor` and `IsVariant` derives now generate `const fn` functions.
- Static methods derived by `IsVariant` are now marked `#[must_use]`.
  ([#350](https://github.com/JelteF/derive_more/pull/350))
- The `Unwrap` and `IsVariant` derives now generate doc comments.
- `#[automatically_derived]` is now emitted from all macro expansions. This
  should prevent code style linters from attempting to modify the generated
  code.
- Upgrade to `syn` 2.0.
- The `Error` derive now works in nightly `no_std` environments

### Fixed

- Use a deterministic `HashSet` in all derives, this is needed for rust analyzer
  to work correctly.
- Use `Provider` API for backtraces in `Error` derive.
- Fix `Error` derive not working with `const` generics.
- Support trait objects for source in Error, e.g.
  `Box<dyn Error + Send + 'static>`
- Fix bounds on derived `IntoIterator` impls for generic structs.
  ([#284](https://github.com/JelteF/derive_more/pull/284))
- Fix documentation of generated bounds in `Display` derive.
  ([#297](https://github.com/JelteF/derive_more/pull/297))
- Hygiene of macro expansions in presence of custom `core` crate.
  ([#327](https://github.com/JelteF/derive_more/pull/327))
- Fix documentation of generated methods in `IsVariant` derive.
- Make `{field:p}` do the expected thing in format strings for `Display` and
  `Debug`. Also document weirdness around `Pointer` formatting when using
  expressions, due to field variables being references.
  ([#381](https://github.com/JelteF/derive_more/pull/381))

This seems pretty significant.

list-rdeps.sh says:

Versions of rust-derive-more in unstable:
  librust-derive-more-dev                          0.99.17-1+b1    

Versions of rdeps of rust-derive-more in unstable, that also exist in testing:
  librust-eww-shared-util-dev                      0.1.0-1+b1       depends on     librust-derive-more-0.99+default-dev, 
  librust-magic-wormhole-dev                       0.7.0-2          depends on     librust-derive-more-0.99+deref-dev, librust-derive-more-0.99+display-dev, librust-derive-more-0.99+from-dev, 
  librust-ruzstd-dev                               0.5.0-1          depends on     librust-derive-more-0.99+display-dev, librust-derive-more-0.99+error-dev, librust-derive-more-0.99+from-dev, 
  librust-selectors-dev                            0.25.0-2+b1      depends on     librust-derive-more-0.99+add-assign-dev, librust-derive-more-0.99+add-dev, 

Source packages in unstable whose autopkgtests are triggered by rust-derive-more:
  rust-async-zip                                   0.0.16-3         triggered by     librust-derive-more-dev=0.99.17-1+b1
  rust-crdts                                       7.3.2+dfsg-5     triggered by     librust-derive-more-dev=0.99.17-1+b1

I'm inclined to package the older version rust-derive-more-0.99 (and update it to 0.99.18 there) while moving rust-derive-more to the 1.x branch. That should make it easier for dependent packages to try the transition at their own pace.

rust-pgp 0.14.0 needs the 1.x branch, which is what is motivating this work.

If anyone objects or wants to propose a different way forward, please suggest it here.

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