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allow clippy::bad_bit_mask in generated Debug impl #373

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ComputerDruid
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Nightly clippy seems to have learned to be able to see 0 values in fields of const structs. This is causing a bunch of warnings in bitflags usages which have consts defined as 0.

I only see this issue on the 1.0 branch.

Example reproducing the issue:

use bitflags::bitflags;

bitflags! {
    struct Foo : u32 {
        const BAR = 0;
    }
}

fn main() {
    let f = Foo::BAR;
    dbg!(f);
}

@KodrAus
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KodrAus commented Jul 10, 2023

Hi @ComputerDruid 👋

Thanks for the PR! Unless there's some critical safety issue that requires patching I don't think we'll make any more releases of 1.x. If possible, upgrading to 2.x would be the way to go, which doesn't require any major version bumps in your own libraries.

stefano-garzarella added a commit to stefano-garzarella/svsm that referenced this pull request Aug 25, 2023
Commit a94d48d ("SVSM/sev/utils: Suppress clippy::bad_bit_mask errors")
was necessary because we use an older version of bitflags.
As suggested in this [1] bitflags issue, let's switch to the latest
version available. In this way we can avoid to suppress
clippy::bad_bit_mask.

Just minor adjustments needed to support bitflags 2.4.0.

[1] bitflags/bitflags#373

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
stefano-garzarella added a commit to stefano-garzarella/svsm that referenced this pull request Aug 25, 2023
Commit a94d48d ("SVSM/sev/utils: Suppress clippy::bad_bit_mask errors")
was necessary because we use an older version of bitflags.
As suggested in this [1] bitflags issue, let's switch to the latest
version available. In this way we can avoid to suppress
clippy::bad_bit_mask.

Just minor adjustments are needed to support bitflags 2.4.0.

[1] bitflags/bitflags#373

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
asomers added a commit to asomers/nix that referenced this pull request Aug 28, 2023
This reverts commit 0c3afc2.

This rolls back the version of bitflags used to 1.1.  Upgrading bitflags
to 2.0 inadvertently caused breaking changes in the r0.26 branch, by
virtue of the methods that the bitflags! macro adds.

Also, mask the bad_bit_mask lint, triggered by bitflags's generated
code.  That lint was the motivation for upgrading bitflags in the first
place.  The bitflags maintainers have decided not to fix those warnings
in the 1.x release series.
bitflags/bitflags#373

Fixes nix-rust#2112
stefano-garzarella added a commit to stefano-garzarella/svsm that referenced this pull request Aug 29, 2023
Commit a94d48d ("SVSM/sev/utils: Suppress clippy::bad_bit_mask errors")
was necessary because we use an older version of bitflags.
As suggested in this [1] bitflags issue, let's switch to the latest
version available. In this way we can avoid to suppress
clippy::bad_bit_mask.

Just minor adjustments are needed to support bitflags 2.4.0.

[1] bitflags/bitflags#373

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
vlovich added a commit to vlovich/glommio that referenced this pull request Oct 5, 2023
Resolves clippy errors that are now caught: bitflags/bitflags#373
vlovich added a commit to vlovich/glommio that referenced this pull request Oct 5, 2023
Resolves clippy errors that are now caught: bitflags/bitflags#373
glommer pushed a commit to DataDog/glommio that referenced this pull request Oct 6, 2023
* fix CI: Bump minimum version to 1.65

backtrace picked up a new addr2line in a patch release that depends on
1.65.

* Fix Cargo warning about resolver

```
warning: some crates are on edition 2021 which defaults to `resolver = "2"`, but virtual workspaces default to `resolver = "1"`
note: to keep the current resolver, specify `workspace.resolver = "1"` in the workspace root's manifest
note: to use the edition 2021 resolver, specify `workspace.resolver = "2"` in the workspace root's manifest
```

* Fix clippy warnings in newer Rust compilers.

* Upgrade to bitflags 2

Resolves clippy errors that are now caught: bitflags/bitflags#373

* Add test highlighting the problem

* Fix background thread pool unbound placement

Any threads we spawn inherit our affinity. This means that background
thread pools for any executors that don't have an affinity of "Unbound"
will only ever run on the executor's CPU rather than distributing work
across many CPUs. This seems undesirable given that the background
thread pool placement can be set independent of the executor it's
associated with. Additionally, the background thread pool placement by
default uses the pool placement so this has no impact on background
threads that didn't have a custom placement set (& if the placement was
set, it was likely the wrong thing happening).
MarijnS95 added a commit to MarijnS95/libv4l-rs that referenced this pull request Nov 9, 2023
CI throws an `clippy::bad_bit_mask` that has been fixed in `bitflags 2`
[1], and it is always a good idea to stay up to date with the latest
crate releases.

The major change is an internal restructuring into _two_ types, that
require the user to now re-expose default traits implemented on the inner
type to the outer type by `#[derive]`'ing them.

[1]: bitflags/bitflags#373
@dtolnay dtolnay closed this Jan 15, 2024
facebook-github-bot pushed a commit to facebook/ocamlrep that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebookexperimental/reverie that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebook/errpy that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebookincubator/antlir that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Test Plan: dall_e_sandcastle_mondrian_style

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebookexperimental/hermit that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebook/hhvm that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebookincubator/below that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
facebook-github-bot pushed a commit to facebook/sapling that referenced this pull request Jan 16, 2024
Summary:
## Motivation

Since the latest compiler update, we are getting `clippy::bad_bit_mask` errors at the callsites of `bitflags!` macros where one of the variant is zero.
[Upstream won't address it in the `1.x` branch](bitflags/bitflags#373) and recommends upgrading to the `2.x` branch.

We are very close to reaching **zero clippy lints** in [Mononoke and other servers](https://fburl.com/code/pd76yn5e), which would feel nice.

## Specific categories of changes (in case it helps with the code review)

The change from `1.x` to `2.x` introduces a number  of backward compatibility breakages which I had to workaround in our codebase.
See [the release notes for 2.0](https://github.com/bitflags/bitflags/releases/tag/2.0.0) for the explanation for the manual fixes I had to perform at each call site.
 ---
**Adding traits to derive:**
```
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Clone, Copy)]
```
> Generated flags types now derive fewer traits. If you need to maintain backwards compatibility, you can derive the following yourself:
 ---
**Replacing read uses of `.bits` with `.bits()`**
> You can now use the .bits() method instead of the old .bits.
> The representation of generated flags types has changed from a struct with the single field bits to a newtype.
 ---
**Replacing raw setting of `.bits` with `.from_bits_retain()`**
Due to the point above, the representation of the type is not exposed anymore. From [the documentation](https://docs.rs/bitflags/latest/bitflags/example_generated/struct.Flags.html#method.from_bits_retain), `from_bits_retain` "convert from a bits value exactly", which matches the old behaviour
 ---
**Replacing the unsafe `from_bits_unchecked` method with `from_bits_retain`**
> The unsafe from_bits_unchecked method is now a safe from_bits_retain method.
 ---
**Extracting some structs outside of the `bitflags!` macro**
Apart from the derives that `bitflags` knows about, such as `serde`, `bitflags` now can't deal with custom derives in macros with the previous syntax. I followed the recommendation from [their documentation](https://docs.rs/bitflags/latest/bitflags/index.html#custom-derives) to declare the `struct` ahead of of the macro call and only declare the `impl` block inside the macro.
 ---
**Changes to test output**
This does not stand out in the release notes, but as of [this upstream PR](bitflags/bitflags#297), the `Debug` output of generated bitflags has changed. This means any tests that rely on this (and of course, there are a few) needed updating.
In particular, the `vespa` tests rely on that output in a non-obvious way. You might have to trust me (and CI) on these ones...

Reviewed By: dtolnay

Differential Revision: D49742979

fbshipit-source-id: c818c37af45f0964e8fdb7ec6173ad66bb982c00
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3 participants