Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 1196 insertions, 0 deletions

diff --git a/third_party/rust/enumset/src/lib.rs b/third_party/rust/enumset/src/lib.rs
new file mode 100644
index 0000000000..5f098f8f5c
--- /dev/null
+++ b/third_party/rust/enumset/src/lib.rs
@@ -0,0 +1,971 @@
+#![no_std]
+#![forbid(missing_docs)]
+// The safety requirement is "use the procedural derive".
+#![allow(clippy::missing_safety_doc)]
+
+//! A library for defining enums that can be used in compact bit sets. It supports enums up to 128
+//! variants, and has a macro to use these sets in constants.
+//!
+//! For serde support, enable the `serde` feature.
+//!
+//! # Defining enums for use with EnumSet
+//!
+//! Enums to be used with [`EnumSet`] should be defined using `#[derive(EnumSetType)]`:
+//!
+//! ```rust
+//! # use enumset::*;
+//! #[derive(EnumSetType, Debug)]
+//! pub enum Enum {
+//!    A, B, C, D, E, F, G,
+//! }
+//! ```
+//!
+//! For more information on more advanced use cases, see the documentation for
+//! [`#[derive(EnumSetType)]`](./derive.EnumSetType.html).
+//!
+//! # Working with EnumSets
+//!
+//! EnumSets can be constructed via [`EnumSet::new()`] like a normal set. In addition,
+//! `#[derive(EnumSetType)]` creates operator overloads that allow you to create EnumSets like so:
+//!
+//! ```rust
+//! # use enumset::*;
+//! # #[derive(EnumSetType, Debug)] pub enum Enum { A, B, C, D, E, F, G }
+//! let new_set = Enum::A | Enum::C | Enum::G;
+//! assert_eq!(new_set.len(), 3);
+//! ```
+//!
+//! All bitwise operations you would expect to work on bitsets also work on both EnumSets and
+//! enums with `#[derive(EnumSetType)]`:
+//! ```rust
+//! # use enumset::*;
+//! # #[derive(EnumSetType, Debug)] pub enum Enum { A, B, C, D, E, F, G }
+//! // Intersection of sets
+//! assert_eq!((Enum::A | Enum::B) & Enum::C, EnumSet::empty());
+//! assert_eq!((Enum::A | Enum::B) & Enum::A, Enum::A);
+//! assert_eq!(Enum::A & Enum::B, EnumSet::empty());
+//!
+//! // Symmetric difference of sets
+//! assert_eq!((Enum::A | Enum::B) ^ (Enum::B | Enum::C), Enum::A | Enum::C);
+//! assert_eq!(Enum::A ^ Enum::C, Enum::A | Enum::C);
+//!
+//! // Difference of sets
+//! assert_eq!((Enum::A | Enum::B | Enum::C) - Enum::B, Enum::A | Enum::C);
+//!
+//! // Complement of sets
+//! assert_eq!(!(Enum::E | Enum::G), Enum::A | Enum::B | Enum::C | Enum::D | Enum::F);
+//! ```
+//!
+//! The [`enum_set!`] macro allows you to create EnumSets in constant contexts:
+//!
+//! ```rust
+//! # use enumset::*;
+//! # #[derive(EnumSetType, Debug)] pub enum Enum { A, B, C, D, E, F, G }
+//! const CONST_SET: EnumSet<Enum> = enum_set!(Enum::A | Enum::B);
+//! assert_eq!(CONST_SET, Enum::A | Enum::B);
+//! ```
+//!
+//! Mutable operations on the [`EnumSet`] otherwise similarly to Rust's builtin sets:
+//!
+//! ```rust
+//! # use enumset::*;
+//! # #[derive(EnumSetType, Debug)] pub enum Enum { A, B, C, D, E, F, G }
+//! let mut set = EnumSet::new();
+//! set.insert(Enum::A);
+//! set.insert_all(Enum::E | Enum::G);
+//! assert!(set.contains(Enum::A));
+//! assert!(!set.contains(Enum::B));
+//! assert_eq!(set, Enum::A | Enum::E | Enum::G);
+//! ```
+
+use core::cmp::Ordering;
+use core::fmt;
+use core::fmt::{Debug, Formatter};
+use core::hash::{Hash, Hasher};
+use core::iter::{FromIterator, Sum};
+use core::ops::*;
+
+#[doc(hidden)]
+/// Everything in this module is internal API and may change at any time.
+pub mod __internal {
+    use super::*;
+
+    /// A reexport of core to allow our macros to be generic to std vs core.
+    pub use ::core as core_export;
+
+    /// A reexport of serde so there is no requirement to depend on serde.
+    #[cfg(feature = "serde")]
+    pub use serde2 as serde;
+
+    /// The actual members of EnumSetType. Put here to avoid polluting global namespaces.
+    pub unsafe trait EnumSetTypePrivate {
+        /// The underlying type used to store the bitset.
+        type Repr: EnumSetTypeRepr;
+        /// A mask of bits that are valid in the bitset.
+        const ALL_BITS: Self::Repr;
+
+        /// Converts an enum of this type into its bit position.
+        fn enum_into_u32(self) -> u32;
+        /// Converts a bit position into an enum value.
+        unsafe fn enum_from_u32(val: u32) -> Self;
+
+        /// Serializes the `EnumSet`.
+        ///
+        /// This and `deserialize` are part of the `EnumSetType` trait so the procedural derive
+        /// can control how `EnumSet` is serialized.
+        #[cfg(feature = "serde")]
+        fn serialize<S: serde::Serializer>(set: EnumSet<Self>, ser: S) -> Result<S::Ok, S::Error>
+        where Self: EnumSetType;
+        /// Deserializes the `EnumSet`.
+        #[cfg(feature = "serde")]
+        fn deserialize<'de, D: serde::Deserializer<'de>>(de: D) -> Result<EnumSet<Self>, D::Error>
+        where Self: EnumSetType;
+    }
+}
+#[cfg(feature = "serde")]
+use crate::__internal::serde;
+use crate::__internal::EnumSetTypePrivate;
+#[cfg(feature = "serde")]
+use crate::serde::{Deserialize, Serialize};
+
+mod repr;
+use crate::repr::EnumSetTypeRepr;
+
+/// The procedural macro used to derive [`EnumSetType`], and allow enums to be used with
+/// [`EnumSet`].
+///
+/// It may be used with any enum with no data fields, at most 127 variants, and no variant
+/// discriminators larger than 127.
+///
+/// # Additional Impls
+///
+/// In addition to the implementation of `EnumSetType`, this procedural macro creates multiple
+/// other impls that are either required for the macro to work, or make the procedural macro more
+/// ergonomic to use.
+///
+/// A full list of traits implemented as is follows:
+///
+/// * [`Copy`], [`Clone`], [`Eq`], [`PartialEq`] implementations are created to allow `EnumSet`
+///   to function properly. These automatic implementations may be suppressed using
+///   `#[enumset(no_super_impls)]`, but these traits must still be implemented in another way.
+/// * [`PartialEq`], [`Sub`], [`BitAnd`], [`BitOr`], [`BitXor`], and [`Not`] implementations are
+///   created to allow the crate to be used more ergonomically in expressions. These automatic
+///   implementations may be suppressed using `#[enumset(no_ops)]`.
+///
+/// # Options
+///
+/// Options are given with `#[enumset(foo)]` annotations attached to the same enum as the derive.
+/// Multiple options may be given in the same annotation using the `#[enumset(foo, bar)]` syntax.
+///
+/// A full list of options is as follows:
+///
+/// * `#[enumset(no_super_impls)]` prevents the derive from creating implementations required for
+///   [`EnumSet`] to function. When this attribute is specified, implementations of [`Copy`],
+///   [`Clone`], [`Eq`], and [`PartialEq`]. This can be useful if you are using a code generator
+///   that already derives these traits. These impls should function identically to the
+///   automatically derived versions, or unintentional behavior may be a result.
+/// * `#[enumset(no_ops)` prevents the derive from implementing any operator traits.
+/// * `#[enumset(crate_name = "enumset2")]` may be used to change the name of the `enumset` crate
+///   used in the generated code. When the `std` feature is enabled, enumset parses `Cargo.toml`
+///   to determine the name of the crate, and this flag is unnecessary.
+/// * `#[enumset(repr = "u8")]` may be used to specify the in-memory representation of `EnumSet`s
+///   of this enum type. The effects of this are described in [the `EnumSet` documentation under
+///   “FFI, Safety and `repr`”][EnumSet#ffi-safety-and-repr]. Allowed types are `u8`, `u16`, `u32`,
+///   `u64` and `u128`. If this is not used, then the derive macro will choose a type to best fit
+///   the enum, but there are no guarantees about which type will be chosen.
+///
+/// When the `serde` feature is used, the following features may also be specified. These options
+/// may be used (with no effect) when building without the feature enabled:
+///
+/// * `#[enumset(serialize_repr = "u8")]` may be used to specify the integer type used to serialize
+///   the underlying bitset. Any type allowed in the `repr` option may be used in this option.
+/// * `#[enumset(serialize_as_list)]` may be used to serialize the bitset as a list of enum
+///   variants instead of an integer. This requires [`Deserialize`] and [`Serialize`] be
+///   implemented on the enum.
+/// * `#[enumset(serialize_deny_unknown)]` causes the generated deserializer to return an error
+///   for unknown bits instead of silently ignoring them.
+///
+/// # Examples
+///
+/// Deriving a plain EnumSetType:
+///
+/// ```rust
+/// # use enumset::*;
+/// #[derive(EnumSetType)]
+/// pub enum Enum {
+///    A, B, C, D, E, F, G,
+/// }
+/// ```
+///
+/// Deriving a sparse EnumSetType:
+///
+/// ```rust
+/// # use enumset::*;
+/// #[derive(EnumSetType)]
+/// pub enum SparseEnum {
+///    A = 10, B = 20, C = 30, D = 127,
+/// }
+/// ```
+///
+/// Deriving an EnumSetType without adding ops:
+///
+/// ```rust
+/// # use enumset::*;
+/// #[derive(EnumSetType)]
+/// #[enumset(no_ops)]
+/// pub enum NoOpsEnum {
+///    A, B, C, D, E, F, G,
+/// }
+/// ```
+pub use enumset_derive::EnumSetType;
+
+/// The trait used to define enum types that may be used with [`EnumSet`].
+///
+/// This trait must be impelmented using `#[derive(EnumSetType)]`, is not public API, and its
+/// internal structure may change at any time with no warning.
+///
+/// For full documentation on the procedural derive and its options, see
+/// [`#[derive(EnumSetType)]`](./derive.EnumSetType.html).
+pub unsafe trait EnumSetType: Copy + Eq + EnumSetTypePrivate {}
+
+/// An [`EnumSetType`] for which [`EnumSet`]s have a guaranteed in-memory representation.
+///
+/// An implementation of this trait is generated by using
+/// [`#[derive(EnumSetType)]`](./derive.EnumSetType.html) with the annotation
+/// `#[enumset(repr = "…")]`, where `…` is `u8`, `u16`, `u32`, `u64` or `u128`.
+///
+/// For any type `T` that implements this trait, the in-memory representation of `EnumSet<T>`
+/// is guaranteed to be `Repr`. This guarantee is useful for FFI. See [the `EnumSet` documentation
+/// under “FFI, Safety and `repr`”][EnumSet#ffi-safety-and-repr] for an example.
+pub unsafe trait EnumSetTypeWithRepr:
+    EnumSetType + EnumSetTypePrivate<Repr = <Self as EnumSetTypeWithRepr>::Repr>
+{
+    /// The guaranteed representation.
+    type Repr: EnumSetTypeRepr;
+}
+
+/// An efficient set type for enums.
+///
+/// It is implemented using a bitset stored using the smallest integer that can fit all bits
+/// in the underlying enum. In general, an enum variant with a discriminator of `n` is stored in
+/// the nth least significant bit (corresponding with a mask of, e.g. `1 << enum as u32`).
+///
+/// # Numeric representation
+///
+/// `EnumSet` is internally implemented using integer types, and as such can be easily converted
+/// from and to numbers.
+///
+/// Each bit of the underlying integer corresponds to at most one particular enum variant. If the
+/// corresponding bit for a variant is set, it present in the set. Bits that do not correspond to
+/// any variant are always unset.
+///
+/// By default, each enum variant is stored in a bit corresponding to its discriminator. An enum
+/// variant with a discriminator of `n` is stored in the `n + 1`th least significant bit
+/// (corresponding to a mask of e.g. `1 << enum as u32`).
+///
+/// # Serialization
+///
+/// When the `serde` feature is enabled, `EnumSet`s can be serialized and deserialized using
+/// the `serde` crate. The exact serialization format can be controlled with additional attributes
+/// on the enum type. These attributes are valid regardless of whether the `serde` feature
+/// is enabled.
+///
+/// By default, `EnumSet`s serialize by directly writing out the underlying bitset as an integer
+/// of the smallest type that can fit in the underlying enum. You can add a
+/// `#[enumset(serialize_repr = "u8")]` attribute to your enum to control the integer type used
+/// for serialization. This can be important for avoiding unintentional breaking changes when
+/// `EnumSet`s are serialized with formats like `bincode`.
+///
+/// By default, unknown bits are ignored and silently removed from the bitset. To override thris
+/// behavior, you can add a `#[enumset(serialize_deny_unknown)]` attribute. This will cause
+/// deserialization to fail if an invalid bit is set.
+///
+/// In addition, the `#[enumset(serialize_as_list)]` attribute causes the `EnumSet` to be
+/// instead serialized as a list of enum variants. This requires your enum type implement
+/// [`Serialize`] and [`Deserialize`]. Note that this is a breaking change.
+///
+/// # FFI, Safety and `repr`
+///
+/// If an enum type `T` is annotated with [`#[enumset(repr = "R")]`][derive@EnumSetType#options],
+/// then several things happen:
+///
+/// * `T` will implement <code>[EnumSetTypeWithRepr]&lt;Repr = R&gt;</code> in addition to
+///   [`EnumSetType`].
+/// * The `EnumSet` methods with `repr` in their name, such as [`as_repr`][EnumSet::as_repr] and
+///   [`from_repr`][EnumSet::from_repr], will be available for `EnumSet<T>`.
+/// * The in-memory representation of `EnumSet<T>` is guaranteed to be `R`.
+///
+/// That last guarantee makes it sound to send `EnumSet<T>` across an FFI boundary. For example:
+///
+/// ```
+/// # use enumset::*;
+/// #
+/// # mod ffi_impl {
+/// #     // This example “foreign” function is actually written in Rust, but for the sake
+/// #     // of example, we'll pretend it's written in C.
+/// #     #[no_mangle]
+/// #     extern "C" fn some_foreign_function(set: u32) -> u32 {
+/// #         set & 0b100
+/// #     }
+/// # }
+/// #
+/// extern "C" {
+///     // This function is written in C like:
+///     // uint32_t some_foreign_function(uint32_t set) { … }
+///     fn some_foreign_function(set: EnumSet<MyEnum>) -> EnumSet<MyEnum>;
+/// }
+///
+/// #[derive(Debug, EnumSetType)]
+/// #[enumset(repr = "u32")]
+/// enum MyEnum { A, B, C }
+///
+/// let set: EnumSet<MyEnum> = enum_set!(MyEnum::A | MyEnum::C);
+///
+/// let new_set: EnumSet<MyEnum> = unsafe { some_foreign_function(set) };
+/// assert_eq!(new_set, enum_set!(MyEnum::C));
+/// ```
+///
+/// When an `EnumSet<T>` is received via FFI, all bits that don't correspond to an enum variant
+/// of `T` must be set to `0`. Behavior is **undefined** if any of these bits are set to `1`.
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(transparent)]
+pub struct EnumSet<T: EnumSetType> {
+    #[doc(hidden)]
+    /// This is public due to the [`enum_set!`] macro.
+    /// This is **NOT** public API and may change at any time.
+    pub __priv_repr: T::Repr,
+}
+impl<T: EnumSetType> EnumSet<T> {
+    // Returns all bits valid for the enum
+    #[inline(always)]
+    fn all_bits() -> T::Repr {
+        T::ALL_BITS
+    }
+
+    /// Creates an empty `EnumSet`.
+    #[inline(always)]
+    pub fn new() -> Self {
+        EnumSet { __priv_repr: T::Repr::empty() }
+    }
+
+    /// Returns an `EnumSet` containing a single element.
+    #[inline(always)]
+    pub fn only(t: T) -> Self {
+        let mut set = Self::new();
+        set.insert(t);
+        set
+    }
+
+    /// Creates an empty `EnumSet`.
+    ///
+    /// This is an alias for [`EnumSet::new`].
+    #[inline(always)]
+    pub fn empty() -> Self {
+        Self::new()
+    }
+
+    /// Returns an `EnumSet` containing all valid variants of the enum.
+    #[inline(always)]
+    pub fn all() -> Self {
+        EnumSet { __priv_repr: Self::all_bits() }
+    }
+
+    /// Total number of bits used by this type. Note that the actual amount of space used is
+    /// rounded up to the next highest integer type (`u8`, `u16`, `u32`, `u64`, or `u128`).
+    ///
+    /// This is the same as [`EnumSet::variant_count`] except in enums with "sparse" variants.
+    /// (e.g. `enum Foo { A = 10, B = 20 }`)
+    #[inline(always)]
+    pub fn bit_width() -> u32 {
+        T::Repr::WIDTH - T::ALL_BITS.leading_zeros()
+    }
+
+    /// The number of valid variants that this type can contain.
+    ///
+    /// This is the same as [`EnumSet::bit_width`] except in enums with "sparse" variants.
+    /// (e.g. `enum Foo { A = 10, B = 20 }`)
+    #[inline(always)]
+    pub fn variant_count() -> u32 {
+        T::ALL_BITS.count_ones()
+    }
+
+    /// Returns the number of elements in this set.
+    #[inline(always)]
+    pub fn len(&self) -> usize {
+        self.__priv_repr.count_ones() as usize
+    }
+    /// Returns `true` if the set contains no elements.
+    #[inline(always)]
+    pub fn is_empty(&self) -> bool {
+        self.__priv_repr.is_empty()
+    }
+    /// Removes all elements from the set.
+    #[inline(always)]
+    pub fn clear(&mut self) {
+        self.__priv_repr = T::Repr::empty()
+    }
+
+    /// Returns `true` if `self` has no elements in common with `other`. This is equivalent to
+    /// checking for an empty intersection.
+    #[inline(always)]
+    pub fn is_disjoint(&self, other: Self) -> bool {
+        (*self & other).is_empty()
+    }
+    /// Returns `true` if the set is a superset of another, i.e., `self` contains at least all the
+    /// values in `other`.
+    #[inline(always)]
+    pub fn is_superset(&self, other: Self) -> bool {
+        (*self & other).__priv_repr == other.__priv_repr
+    }
+    /// Returns `true` if the set is a subset of another, i.e., `other` contains at least all
+    /// the values in `self`.
+    #[inline(always)]
+    pub fn is_subset(&self, other: Self) -> bool {
+        other.is_superset(*self)
+    }
+
+    /// Returns a set containing any elements present in either set.
+    #[inline(always)]
+    pub fn union(&self, other: Self) -> Self {
+        EnumSet { __priv_repr: self.__priv_repr | other.__priv_repr }
+    }
+    /// Returns a set containing every element present in both sets.
+    #[inline(always)]
+    pub fn intersection(&self, other: Self) -> Self {
+        EnumSet { __priv_repr: self.__priv_repr & other.__priv_repr }
+    }
+    /// Returns a set containing element present in `self` but not in `other`.
+    #[inline(always)]
+    pub fn difference(&self, other: Self) -> Self {
+        EnumSet { __priv_repr: self.__priv_repr.and_not(other.__priv_repr) }
+    }
+    /// Returns a set containing every element present in either `self` or `other`, but is not
+    /// present in both.
+    #[inline(always)]
+    pub fn symmetrical_difference(&self, other: Self) -> Self {
+        EnumSet { __priv_repr: self.__priv_repr ^ other.__priv_repr }
+    }
+    /// Returns a set containing all enum variants not in this set.
+    #[inline(always)]
+    pub fn complement(&self) -> Self {
+        EnumSet { __priv_repr: !self.__priv_repr & Self::all_bits() }
+    }
+
+    /// Checks whether this set contains a value.
+    #[inline(always)]
+    pub fn contains(&self, value: T) -> bool {
+        self.__priv_repr.has_bit(value.enum_into_u32())
+    }
+
+    /// Adds a value to this set.
+    ///
+    /// If the set did not have this value present, `true` is returned.
+    ///
+    /// If the set did have this value present, `false` is returned.
+    #[inline(always)]
+    pub fn insert(&mut self, value: T) -> bool {
+        let contains = !self.contains(value);
+        self.__priv_repr.add_bit(value.enum_into_u32());
+        contains
+    }
+    /// Removes a value from this set. Returns whether the value was present in the set.
+    #[inline(always)]
+    pub fn remove(&mut self, value: T) -> bool {
+        let contains = self.contains(value);
+        self.__priv_repr.remove_bit(value.enum_into_u32());
+        contains
+    }
+
+    /// Adds all elements in another set to this one.
+    #[inline(always)]
+    pub fn insert_all(&mut self, other: Self) {
+        self.__priv_repr = self.__priv_repr | other.__priv_repr
+    }
+    /// Removes all values in another set from this one.
+    #[inline(always)]
+    pub fn remove_all(&mut self, other: Self) {
+        self.__priv_repr = self.__priv_repr.and_not(other.__priv_repr);
+    }
+
+    /// Iterates the contents of the set in order from the least significant bit to the most
+    /// significant bit.
+    ///
+    /// Note that iterator invalidation is impossible as the iterator contains a copy of this type,
+    /// rather than holding a reference to it.
+    pub fn iter(&self) -> EnumSetIter<T> {
+        EnumSetIter::new(*self)
+    }
+
+    /// Returns a `T::Repr` representing the elements of this set.
+    ///
+    /// Unlike the other `as_*` methods, this method is zero-cost and guaranteed not to fail,
+    /// panic or truncate any bits.
+    ///
+    /// In order to use this method, the definition of `T` must have the `#[enumset(repr = "…")]`
+    /// annotation.
+    #[inline(always)]
+    pub fn as_repr(&self) -> <T as EnumSetTypeWithRepr>::Repr
+    where T: EnumSetTypeWithRepr {
+        self.__priv_repr
+    }
+
+    /// Constructs a bitset from a `T::Repr` without checking for invalid bits.
+    ///
+    /// Unlike the other `from_*` methods, this method is zero-cost and guaranteed not to fail,
+    /// panic or truncate any bits, provided the conditions under “Safety” are upheld.
+    ///
+    /// In order to use this method, the definition of `T` must have the `#[enumset(repr = "…")]`
+    /// annotation.
+    ///
+    /// # Safety
+    ///
+    /// All bits in the provided parameter `bits` that don't correspond to an enum variant of
+    /// `T` must be set to `0`. Behavior is **undefined** if any of these bits are set to `1`.
+    #[inline(always)]
+    pub unsafe fn from_repr_unchecked(bits: <T as EnumSetTypeWithRepr>::Repr) -> Self
+    where T: EnumSetTypeWithRepr {
+        Self { __priv_repr: bits }
+    }
+
+    /// Constructs a bitset from a `T::Repr`.
+    ///
+    /// If a bit that doesn't correspond to an enum variant is set, this
+    /// method will panic.
+    ///
+    /// In order to use this method, the definition of `T` must have the `#[enumset(repr = "…")]`
+    /// annotation.
+    #[inline(always)]
+    pub fn from_repr(bits: <T as EnumSetTypeWithRepr>::Repr) -> Self
+    where T: EnumSetTypeWithRepr {
+        Self::try_from_repr(bits).expect("Bitset contains invalid variants.")
+    }
+
+    /// Attempts to constructs a bitset from a `T::Repr`.
+    ///
+    /// If a bit that doesn't correspond to an enum variant is set, this
+    /// method will return `None`.
+    ///
+    /// In order to use this method, the definition of `T` must have the `#[enumset(repr = "…")]`
+    /// annotation.
+    #[inline(always)]
+    pub fn try_from_repr(bits: <T as EnumSetTypeWithRepr>::Repr) -> Option<Self>
+    where T: EnumSetTypeWithRepr {
+        let mask = Self::all().__priv_repr;
+        if bits.and_not(mask).is_empty() {
+            Some(EnumSet { __priv_repr: bits })
+        } else {
+            None
+        }
+    }
+
+    /// Constructs a bitset from a `T::Repr`, ignoring invalid variants.
+    ///
+    /// In order to use this method, the definition of `T` must have the `#[enumset(repr = "…")]`
+    /// annotation.
+    #[inline(always)]
+    pub fn from_repr_truncated(bits: <T as EnumSetTypeWithRepr>::Repr) -> Self
+    where T: EnumSetTypeWithRepr {
+        let mask = Self::all().as_repr();
+        let bits = bits & mask;
+        EnumSet { __priv_repr: bits }
+    }
+}
+
+/// Helper macro for generating conversion functions.
+macro_rules! conversion_impls {
+    (
+        $(for_num!(
+            $underlying:ty, $underlying_str:expr,
+            $from_fn:ident $to_fn:ident $from_fn_opt:ident $to_fn_opt:ident,
+            $from:ident $try_from:ident $from_truncated:ident $from_unchecked:ident,
+            $to:ident $try_to:ident $to_truncated:ident
+        );)*
+    ) => {
+        impl <T : EnumSetType> EnumSet<T> {$(
+            #[doc = "Returns a `"]
+            #[doc = $underlying_str]
+            #[doc = "` representing the elements of this set.\n\nIf the underlying bitset will \
+                     not fit in a `"]
+            #[doc = $underlying_str]
+            #[doc = "` or contains bits that do not correspond to an enum variant, this method \
+                     will panic."]
+            #[inline(always)]
+            pub fn $to(&self) -> $underlying {
+                self.$try_to().expect("Bitset will not fit into this type.")
+            }
+
+            #[doc = "Tries to return a `"]
+            #[doc = $underlying_str]
+            #[doc = "` representing the elements of this set.\n\nIf the underlying bitset will \
+                     not fit in a `"]
+            #[doc = $underlying_str]
+            #[doc = "` or contains bits that do not correspond to an enum variant, this method \
+                     will instead return `None`."]
+            #[inline(always)]
+            pub fn $try_to(&self) -> Option<$underlying> {
+                EnumSetTypeRepr::$to_fn_opt(&self.__priv_repr)
+            }
+
+            #[doc = "Returns a truncated `"]
+            #[doc = $underlying_str]
+            #[doc = "` representing the elements of this set.\n\nIf the underlying bitset will \
+                     not fit in a `"]
+            #[doc = $underlying_str]
+            #[doc = "`, this method will truncate any bits that don't fit or do not correspond \
+                     to an enum variant."]
+            #[inline(always)]
+            pub fn $to_truncated(&self) -> $underlying {
+                EnumSetTypeRepr::$to_fn(&self.__priv_repr)
+            }
+
+            #[doc = "Constructs a bitset from a `"]
+            #[doc = $underlying_str]
+            #[doc = "`.\n\nIf a bit that doesn't correspond to an enum variant is set, this \
+                     method will panic."]
+            #[inline(always)]
+            pub fn $from(bits: $underlying) -> Self {
+                Self::$try_from(bits).expect("Bitset contains invalid variants.")
+            }
+
+            #[doc = "Attempts to constructs a bitset from a `"]
+            #[doc = $underlying_str]
+            #[doc = "`.\n\nIf a bit that doesn't correspond to an enum variant is set, this \
+                     method will return `None`."]
+            #[inline(always)]
+            pub fn $try_from(bits: $underlying) -> Option<Self> {
+                let bits = T::Repr::$from_fn_opt(bits);
+                let mask = Self::all().__priv_repr;
+                bits.and_then(|bits| if bits.and_not(mask).is_empty() {
+                    Some(EnumSet { __priv_repr: bits })
+                } else {
+                    None
+                })
+            }
+
+            #[doc = "Constructs a bitset from a `"]
+            #[doc = $underlying_str]
+            #[doc = "`, ignoring invalid variants."]
+            #[inline(always)]
+            pub fn $from_truncated(bits: $underlying) -> Self {
+                let mask = Self::all().$to_truncated();
+                let bits = <T::Repr as EnumSetTypeRepr>::$from_fn(bits & mask);
+                EnumSet { __priv_repr: bits }
+            }
+
+            #[doc = "Constructs a bitset from a `"]
+            #[doc = $underlying_str]
+            #[doc = "`, without checking for invalid bits."]
+            ///
+            /// # Safety
+            ///
+            /// All bits in the provided parameter `bits` that don't correspond to an enum variant
+            /// of `T` must be set to `0`. Behavior is **undefined** if any of these bits are set
+            /// to `1`.
+            #[inline(always)]
+            pub unsafe fn $from_unchecked(bits: $underlying) -> Self {
+                EnumSet { __priv_repr: <T::Repr as EnumSetTypeRepr>::$from_fn(bits) }
+            }
+        )*}
+    }
+}
+conversion_impls! {
+    for_num!(u8, "u8",
+             from_u8 to_u8 from_u8_opt to_u8_opt,
+             from_u8 try_from_u8 from_u8_truncated from_u8_unchecked,
+             as_u8 try_as_u8 as_u8_truncated);
+    for_num!(u16, "u16",
+             from_u16 to_u16 from_u16_opt to_u16_opt,
+             from_u16 try_from_u16 from_u16_truncated from_u16_unchecked,
+             as_u16 try_as_u16 as_u16_truncated);
+    for_num!(u32, "u32",
+             from_u32 to_u32 from_u32_opt to_u32_opt,
+             from_u32 try_from_u32 from_u32_truncated from_u32_unchecked,
+             as_u32 try_as_u32 as_u32_truncated);
+    for_num!(u64, "u64",
+             from_u64 to_u64 from_u64_opt to_u64_opt,
+             from_u64 try_from_u64 from_u64_truncated from_u64_unchecked,
+             as_u64 try_as_u64 as_u64_truncated);
+    for_num!(u128, "u128",
+             from_u128 to_u128 from_u128_opt to_u128_opt,
+             from_u128 try_from_u128 from_u128_truncated from_u128_unchecked,
+             as_u128 try_as_u128 as_u128_truncated);
+    for_num!(usize, "usize",
+             from_usize to_usize from_usize_opt to_usize_opt,
+             from_usize try_from_usize from_usize_truncated from_usize_unchecked,
+             as_usize try_as_usize as_usize_truncated);
+}
+
+impl<T: EnumSetType> Default for EnumSet<T> {
+    /// Returns an empty set.
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<T: EnumSetType> IntoIterator for EnumSet<T> {
+    type Item = T;
+    type IntoIter = EnumSetIter<T>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+impl<T: EnumSetType> Sum for EnumSet<T> {
+    fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
+        iter.fold(EnumSet::empty(), |a, v| a | v)
+    }
+}
+impl<'a, T: EnumSetType> Sum<&'a EnumSet<T>> for EnumSet<T> {
+    fn sum<I: Iterator<Item = &'a Self>>(iter: I) -> Self {
+        iter.fold(EnumSet::empty(), |a, v| a | *v)
+    }
+}
+impl<T: EnumSetType> Sum<T> for EnumSet<T> {
+    fn sum<I: Iterator<Item = T>>(iter: I) -> Self {
+        iter.fold(EnumSet::empty(), |a, v| a | v)
+    }
+}
+impl<'a, T: EnumSetType> Sum<&'a T> for EnumSet<T> {
+    fn sum<I: Iterator<Item = &'a T>>(iter: I) -> Self {
+        iter.fold(EnumSet::empty(), |a, v| a | *v)
+    }
+}
+
+impl<T: EnumSetType, O: Into<EnumSet<T>>> Sub<O> for EnumSet<T> {
+    type Output = Self;
+    #[inline(always)]
+    fn sub(self, other: O) -> Self::Output {
+        self.difference(other.into())
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitAnd<O> for EnumSet<T> {
+    type Output = Self;
+    #[inline(always)]
+    fn bitand(self, other: O) -> Self::Output {
+        self.intersection(other.into())
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitOr<O> for EnumSet<T> {
+    type Output = Self;
+    #[inline(always)]
+    fn bitor(self, other: O) -> Self::Output {
+        self.union(other.into())
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitXor<O> for EnumSet<T> {
+    type Output = Self;
+    #[inline(always)]
+    fn bitxor(self, other: O) -> Self::Output {
+        self.symmetrical_difference(other.into())
+    }
+}
+
+impl<T: EnumSetType, O: Into<EnumSet<T>>> SubAssign<O> for EnumSet<T> {
+    #[inline(always)]
+    fn sub_assign(&mut self, rhs: O) {
+        *self = *self - rhs;
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitAndAssign<O> for EnumSet<T> {
+    #[inline(always)]
+    fn bitand_assign(&mut self, rhs: O) {
+        *self = *self & rhs;
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitOrAssign<O> for EnumSet<T> {
+    #[inline(always)]
+    fn bitor_assign(&mut self, rhs: O) {
+        *self = *self | rhs;
+    }
+}
+impl<T: EnumSetType, O: Into<EnumSet<T>>> BitXorAssign<O> for EnumSet<T> {
+    #[inline(always)]
+    fn bitxor_assign(&mut self, rhs: O) {
+        *self = *self ^ rhs;
+    }
+}
+
+impl<T: EnumSetType> Not for EnumSet<T> {
+    type Output = Self;
+    #[inline(always)]
+    fn not(self) -> Self::Output {
+        self.complement()
+    }
+}
+
+impl<T: EnumSetType> From<T> for EnumSet<T> {
+    fn from(t: T) -> Self {
+        EnumSet::only(t)
+    }
+}
+
+impl<T: EnumSetType> PartialEq<T> for EnumSet<T> {
+    fn eq(&self, other: &T) -> bool {
+        self.__priv_repr == EnumSet::only(*other).__priv_repr
+    }
+}
+impl<T: EnumSetType + Debug> Debug for EnumSet<T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        let mut is_first = true;
+        f.write_str("EnumSet(")?;
+        for v in self.iter() {
+            if !is_first {
+                f.write_str(" | ")?;
+            }
+            is_first = false;
+            v.fmt(f)?;
+        }
+        f.write_str(")")?;
+        Ok(())
+    }
+}
+
+#[allow(clippy::derive_hash_xor_eq)] // This impl exists to change trait bounds only.
+impl<T: EnumSetType> Hash for EnumSet<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.__priv_repr.hash(state)
+    }
+}
+impl<T: EnumSetType> PartialOrd for EnumSet<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.__priv_repr.partial_cmp(&other.__priv_repr)
+    }
+}
+impl<T: EnumSetType> Ord for EnumSet<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.__priv_repr.cmp(&other.__priv_repr)
+    }
+}
+
+#[cfg(feature = "serde")]
+impl<T: EnumSetType> Serialize for EnumSet<T> {
+    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        T::serialize(*self, serializer)
+    }
+}
+
+#[cfg(feature = "serde")]
+impl<'de, T: EnumSetType> Deserialize<'de> for EnumSet<T> {
+    fn deserialize<D: serde::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
+        T::deserialize(deserializer)
+    }
+}
+
+/// The iterator used by [`EnumSet`]s.
+#[derive(Clone, Debug)]
+pub struct EnumSetIter<T: EnumSetType> {
+    set: EnumSet<T>,
+}
+impl<T: EnumSetType> EnumSetIter<T> {
+    fn new(set: EnumSet<T>) -> EnumSetIter<T> {
+        EnumSetIter { set }
+    }
+}
+
+impl<T: EnumSetType> Iterator for EnumSetIter<T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.set.is_empty() {
+            None
+        } else {
+            let bit = self.set.__priv_repr.trailing_zeros();
+            self.set.__priv_repr.remove_bit(bit);
+            unsafe { Some(T::enum_from_u32(bit)) }
+        }
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let left = self.set.len();
+        (left, Some(left))
+    }
+}
+
+impl<T: EnumSetType> DoubleEndedIterator for EnumSetIter<T> {
+    fn next_back(&mut self) -> Option<Self::Item> {
+        if self.set.is_empty() {
+            None
+        } else {
+            let bit = T::Repr::WIDTH - 1 - self.set.__priv_repr.leading_zeros();
+            self.set.__priv_repr.remove_bit(bit);
+            unsafe { Some(T::enum_from_u32(bit)) }
+        }
+    }
+}
+
+impl<T: EnumSetType> ExactSizeIterator for EnumSetIter<T> {}
+
+impl<T: EnumSetType> Extend<T> for EnumSet<T> {
+    fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
+        iter.into_iter().for_each(|v| {
+            self.insert(v);
+        });
+    }
+}
+
+impl<T: EnumSetType> FromIterator<T> for EnumSet<T> {
+    fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self {
+        let mut set = EnumSet::default();
+        set.extend(iter);
+        set
+    }
+}
+
+impl<T: EnumSetType> Extend<EnumSet<T>> for EnumSet<T> {
+    fn extend<I: IntoIterator<Item = EnumSet<T>>>(&mut self, iter: I) {
+        iter.into_iter().for_each(|v| {
+            self.insert_all(v);
+        });
+    }
+}
+
+impl<T: EnumSetType> FromIterator<EnumSet<T>> for EnumSet<T> {
+    fn from_iter<I: IntoIterator<Item = EnumSet<T>>>(iter: I) -> Self {
+        let mut set = EnumSet::default();
+        set.extend(iter);
+        set
+    }
+}
+
+/// Creates a EnumSet literal, which can be used in const contexts.
+///
+/// The syntax used is `enum_set!(Type::A | Type::B | Type::C)`. Each variant must be of the same
+/// type, or a error will occur at compile-time.
+///
+/// This macro accepts trailing `|`s to allow easier use in other macros.
+///
+/// # Examples
+///
+/// ```rust
+/// # use enumset::*;
+/// # #[derive(EnumSetType, Debug)] enum Enum { A, B, C }
+/// const CONST_SET: EnumSet<Enum> = enum_set!(Enum::A | Enum::B);
+/// assert_eq!(CONST_SET, Enum::A | Enum::B);
+/// ```
+///
+/// This macro is strongly typed. For example, the following will not compile:
+///
+/// ```compile_fail
+/// # use enumset::*;
+/// # #[derive(EnumSetType, Debug)] enum Enum { A, B, C }
+/// # #[derive(EnumSetType, Debug)] enum Enum2 { A, B, C }
+/// let type_error = enum_set!(Enum::A | Enum2::B);
+/// ```
+#[macro_export]
+macro_rules! enum_set {
+    ($(|)*) => {
+        $crate::EnumSet { __priv_repr: 0 }
+    };
+    ($value:path $(|)*) => {
+        {
+            #[allow(deprecated)] let value = $value.__impl_enumset_internal__const_only();
+            value
+        }
+    };
+    ($value:path | $($rest:path)|* $(|)*) => {
+        {
+            #[allow(deprecated)] let value = $value.__impl_enumset_internal__const_only();
+            $(#[allow(deprecated)] let value = $rest.__impl_enumset_internal__const_merge(value);)*
+            value
+        }
+    };
+}
diff --git a/third_party/rust/enumset/src/repr.rs b/third_party/rust/enumset/src/repr.rs
new file mode 100644
index 0000000000..38546aa8c9
--- /dev/null
+++ b/third_party/rust/enumset/src/repr.rs
@@ -0,0 +1,225 @@
+use core::convert::TryInto;
+use core::fmt::Debug;
+use core::hash::Hash;
+use core::ops::*;
+
+/// A trait marking valid underlying bitset storage types and providing the
+/// operations `EnumSet` and related types use.
+pub trait EnumSetTypeRepr :
+    // Basic traits used to derive traits
+    Copy +
+    Ord +
+    Eq +
+    Debug +
+    Hash +
+    // Operations used by enumset
+    BitAnd<Output = Self> +
+    BitOr<Output = Self> +
+    BitXor<Output = Self> +
+    Not<Output = Self> +
+{
+    const WIDTH: u32;
+
+    fn is_empty(&self) -> bool;
+    fn empty() -> Self;
+
+    fn add_bit(&mut self, bit: u32);
+    fn remove_bit(&mut self, bit: u32);
+    fn has_bit(&self, bit: u32) -> bool;
+
+    fn count_ones(&self) -> u32;
+    fn count_remaining_ones(&self, cursor: u32) -> usize;
+    fn leading_zeros(&self) -> u32;
+    fn trailing_zeros(&self) -> u32;
+
+    fn and_not(&self, other: Self) -> Self;
+
+    fn from_u8(v: u8) -> Self;
+    fn from_u16(v: u16) -> Self;
+    fn from_u32(v: u32) -> Self;
+    fn from_u64(v: u64) -> Self;
+    fn from_u128(v: u128) -> Self;
+    fn from_usize(v: usize) -> Self;
+
+    fn to_u8(&self) -> u8;
+    fn to_u16(&self) -> u16;
+    fn to_u32(&self) -> u32;
+    fn to_u64(&self) -> u64;
+    fn to_u128(&self) -> u128;
+    fn to_usize(&self) -> usize;
+
+    fn from_u8_opt(v: u8) -> Option<Self>;
+    fn from_u16_opt(v: u16) -> Option<Self>;
+    fn from_u32_opt(v: u32) -> Option<Self>;
+    fn from_u64_opt(v: u64) -> Option<Self>;
+    fn from_u128_opt(v: u128) -> Option<Self>;
+    fn from_usize_opt(v: usize) -> Option<Self>;
+
+    fn to_u8_opt(&self) -> Option<u8>;
+    fn to_u16_opt(&self) -> Option<u16>;
+    fn to_u32_opt(&self) -> Option<u32>;
+    fn to_u64_opt(&self) -> Option<u64>;
+    fn to_u128_opt(&self) -> Option<u128>;
+    fn to_usize_opt(&self) -> Option<usize>;
+}
+macro_rules! prim {
+    ($name:ty, $width:expr) => {
+        impl EnumSetTypeRepr for $name {
+            const WIDTH: u32 = $width;
+
+            #[inline(always)]
+            fn is_empty(&self) -> bool {
+                *self == 0
+            }
+            #[inline(always)]
+            fn empty() -> Self {
+                0
+            }
+
+            #[inline(always)]
+            fn add_bit(&mut self, bit: u32) {
+                *self |= 1 << bit as $name;
+            }
+            #[inline(always)]
+            fn remove_bit(&mut self, bit: u32) {
+                *self &= !(1 << bit as $name);
+            }
+            #[inline(always)]
+            fn has_bit(&self, bit: u32) -> bool {
+                (self & (1 << bit as $name)) != 0
+            }
+
+            #[inline(always)]
+            fn count_ones(&self) -> u32 {
+                (*self).count_ones()
+            }
+            #[inline(always)]
+            fn leading_zeros(&self) -> u32 {
+                (*self).leading_zeros()
+            }
+            #[inline(always)]
+            fn trailing_zeros(&self) -> u32 {
+                (*self).trailing_zeros()
+            }
+
+            #[inline(always)]
+            fn and_not(&self, other: Self) -> Self {
+                (*self) & !other
+            }
+
+            #[inline(always)]
+            fn count_remaining_ones(&self, cursor: u32) -> usize {
+                let left_mask = !((1 as $name)
+                    .checked_shl(cursor)
+                    .unwrap_or(0)
+                    .wrapping_sub(1));
+                (*self & left_mask).count_ones() as usize
+            }
+
+            #[inline(always)]
+            fn from_u8(v: u8) -> Self {
+                v as $name
+            }
+            #[inline(always)]
+            fn from_u16(v: u16) -> Self {
+                v as $name
+            }
+            #[inline(always)]
+            fn from_u32(v: u32) -> Self {
+                v as $name
+            }
+            #[inline(always)]
+            fn from_u64(v: u64) -> Self {
+                v as $name
+            }
+            #[inline(always)]
+            fn from_u128(v: u128) -> Self {
+                v as $name
+            }
+            #[inline(always)]
+            fn from_usize(v: usize) -> Self {
+                v as $name
+            }
+
+            #[inline(always)]
+            fn to_u8(&self) -> u8 {
+                (*self) as u8
+            }
+            #[inline(always)]
+            fn to_u16(&self) -> u16 {
+                (*self) as u16
+            }
+            #[inline(always)]
+            fn to_u32(&self) -> u32 {
+                (*self) as u32
+            }
+            #[inline(always)]
+            fn to_u64(&self) -> u64 {
+                (*self) as u64
+            }
+            #[inline(always)]
+            fn to_u128(&self) -> u128 {
+                (*self) as u128
+            }
+            #[inline(always)]
+            fn to_usize(&self) -> usize {
+                (*self) as usize
+            }
+
+            #[inline(always)]
+            fn from_u8_opt(v: u8) -> Option<Self> {
+                v.try_into().ok()
+            }
+            #[inline(always)]
+            fn from_u16_opt(v: u16) -> Option<Self> {
+                v.try_into().ok()
+            }
+            #[inline(always)]
+            fn from_u32_opt(v: u32) -> Option<Self> {
+                v.try_into().ok()
+            }
+            #[inline(always)]
+            fn from_u64_opt(v: u64) -> Option<Self> {
+                v.try_into().ok()
+            }
+            #[inline(always)]
+            fn from_u128_opt(v: u128) -> Option<Self> {
+                v.try_into().ok()
+            }
+            #[inline(always)]
+            fn from_usize_opt(v: usize) -> Option<Self> {
+                v.try_into().ok()
+            }
+
+            #[inline(always)]
+            fn to_u8_opt(&self) -> Option<u8> {
+                (*self).try_into().ok()
+            }
+            #[inline(always)]
+            fn to_u16_opt(&self) -> Option<u16> {
+                (*self).try_into().ok()
+            }
+            #[inline(always)]
+            fn to_u32_opt(&self) -> Option<u32> {
+                (*self).try_into().ok()
+            }
+            #[inline(always)]
+            fn to_u64_opt(&self) -> Option<u64> {
+                (*self).try_into().ok()
+            }
+            #[inline(always)]
+            fn to_u128_opt(&self) -> Option<u128> {
+                (*self).try_into().ok()
+            }
+            #[inline(always)]
+            fn to_usize_opt(&self) -> Option<usize> {
+                (*self).try_into().ok()
+            }
+        }
+    };
+}
+prim!(u8, 8);
+prim!(u16, 16);
+prim!(u32, 32);
+prim!(u64, 64);
+prim!(u128, 128);