Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
author: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 00:47:55 +0000
committer: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-04-19 00:47:55 +0000
commit: 26a029d407be480d791972afb5975cf62c9360a6 (patch)
tree: f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/generic-array
parent: Initial commit. (diff)
download: firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
15 files changed, 2299 insertions, 0 deletions
diff --git a/third_party/rust/generic-array/.cargo-checksum.json b/third_party/rust/generic-array/.cargo-checksum.json
new file mode 100644
index 0000000000..f8ddf9aa70
--- /dev/null
+++ b/third_party/rust/generic-array/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGELOG.md":"e1d167ae44b01d58177842db72b8ddf754850756adc40ab87fef6af83ee7f759","Cargo.toml":"d75b1d3d662d67545bc43f331fdfbb95b8e9cb8522875608a7f8f2528e3325d3","LICENSE":"c09aae9d3c77b531f56351a9947bc7446511d6b025b3255312d3e3442a9a7583","README.md":"9e86d03b400dc818f44df68b76dafd1d89e42a51221bcb0de4259a6529ab6d84","build.rs":"08fa30c4a2c1ad24fe5f987e721dfb20131f45ea5b5dc3e836dcf88a8e33248c","src/arr.rs":"c115d6926deb769ced772e9c4e1c84baf1bdea4fe4b9eb2061658a63869eab62","src/functional.rs":"7dd6ddd5db3000054cbbd76959f745c7de73c8493cbfb745be80509b306e4a83","src/hex.rs":"091fb78f6d373a6ef1c467d85c461472fcdb1e91efc294039f4c870151c3ee9f","src/impl_serde.rs":"f046daba067522b4c3e79437d04f43a001e83353c81e6b2188c37a2e63dba7a3","src/impl_zeroize.rs":"b7825efdc72890ed05337f7ebdfb27cc6952126f1c94c855fdafaa24fab0bf2a","src/impls.rs":"18b285821421eea0cdbbcfcc896eef67bd55d72f8d85b5827cca6687e9c0fc27","src/iter.rs":"4f50253f4130caa0780984b64467ca1916a881410f631f7eb85a1724b3ab4ced","src/lib.rs":"163b24f691d59383c9e347126569205b03272145334cbce037cd562b93ad9f30","src/sequence.rs":"26679cfec035bae7298f067f37e8d42a1eda8fe241e9cf2c2977ba4bddddab1d"},"package":"bff49e947297f3312447abdca79f45f4738097cc82b06e72054d2223f601f1b9"}
+\ No newline at end of file
diff --git a/third_party/rust/generic-array/CHANGELOG.md b/third_party/rust/generic-array/CHANGELOG.md
new file mode 100644
index 0000000000..f7e0766bc1
--- /dev/null
+++ b/third_party/rust/generic-array/CHANGELOG.md
@@ -0,0 +1,98 @@
+* **`0.14.6`**
+    * Add an optional `Zeroize` impl for `GenericArray` (#126 and #112)
+    * Cleanup some unsafe (#125) and typos (#114)
+    * Use `include` in `Cargo.toml` to reduce package size
+
+* **`0.14.5`**
+    * Fix unsoundness behavior in `GenericArrayIter::clone` ([#120](https://github.com/fizyk20/generic-array/pull/120))
+
+* **`0.14.4`**
+    * Update `typenum` to `1.12.0`
+    * Make `Drop` a no-op when the inner type does not require `Drop` (using `core::mem::needs_drop`)
+
+* **`0.14.3`**
+    * Improve behavior of `GenericArray::from_exact_iter` to assume `ExactIterator`s can lie.
+    * Fix alignment of zero-length `GenericArray`s
+    * Implement `From<&[T; N]> for &GenericArray<T, N>` and its mutable variant
+
+* **`0.14.2`**
+    * Lower MSRV to `1.36.0` without `From<[T; N]>` implementations.
+
+* **`0.14.1`**
+    * Fix element conversions in `arr!` macro.
+
+* **`0.14.0`**
+    * Replace `Into` implementations with the more general `From`.
+        * Requires minumum Rust version of 1.41.0
+    * Fix unsoundness in `arr!` macro.
+    * Fix meta variable misuse
+    * Fix Undefined Behavior across the crate by switching to `MaybeUninit`
+    * Improve some documentation and doctests
+    * Add `AsRef<[T; N]>` and `AsMut<[T; N]>` impls to `GenericArray<T, N>`
+    * Add `Split` impl for `&GenericArray` and `&mut GenericArray`
+
+* **`0.13.2`**
+    * Add feature `more_lengths`, which adds more `From`/`Into` implementations for arrays of various lengths.
+
+* **`0.13.1`**
+    * Mark `GenericArray` as `#[repr(transparent)]`
+    * Implement `Into<[T; N]>` for `GenericArray<T, N>` up to N=32
+
+* **`0.13.0`**
+    * Allow `arr!` to be imported with use syntax.
+        * Requires minumum Rust version of 1.30.1
+
+* **`0.12.2`**
+    * Implement `FusedIterator` for `GenericArrayIter`
+
+* **`0.12.1`**
+    * Use internal iteration where possible and provide more efficient internal iteration methods.
+
+* **`0.12.0`**
+    * Allow trailing commas in `arr!` macro.
+    * **BREAKING**: Serialize `GenericArray` using `serde` tuples, instead of variable-length sequences. This may not be compatible with old serialized data.
+
+* **`0.11.0`**
+    * **BREAKING** Redesign `GenericSequence` with an emphasis on use in generic type parameters.
+    * Add `MappedGenericSequence` and `FunctionalSequence`
+        * Implements optimized `map`, `zip` and `fold` for `GenericArray`, `&GenericArray` and `&mut GenericArray`
+    * **BREAKING** Remove `map_ref`, `zip_ref` and `map_slice`
+        * `map_slice` is now equivalent to `GenericArray::from_iter(slice.iter().map(...))`
+* **`0.10.0`**
+    * Add `GenericSequence`, `Lengthen`, `Shorten`, `Split` and `Concat` traits.
+    * Redefine `transmute` to avert errors.
+* **`0.9.0`**
+    * Rewrite construction methods to be well-defined in panic situations, correctly dropping elements.
+    * `NoDrop` crate replaced by `ManuallyDrop` as it became stable in Rust core.
+    * Add optimized `map`/`map_ref` and `zip`/`zip_ref` methods to `GenericArray`
+* **`0.8.0`**
+    * Implement `AsRef`, `AsMut`, `Borrow`, `BorrowMut`, `Hash` for `GenericArray`
+    * Update `serde` to `1.0`
+    * Update `typenum`
+    * Make macro `arr!` non-cloning
+    * Implement `From<[T; N]>` up to `N=32`
+    * Fix #45
+* **`0.7.0`**
+    * Upgrade `serde` to `0.9`
+    * Make `serde` with `no_std`
+    * Implement `PartialOrd`/`Ord` for `GenericArray`
+* **`0.6.0`**
+    * Fixed #30
+    * Implement `Default` for `GenericArray`
+    * Implement `LowerHex` and `UpperHex` for `GenericArray<u8, N>`
+    * Use `precision` formatting field in hex representation
+    * Add `as_slice`, `as_mut_slice`
+    * Remove `GenericArray::new` in favor of `Default` trait
+    * Add `from_slice` and `from_mut_slice`
+    * `no_std` and `core` for crate.
+* **`0.5.0`**
+    * Update `serde`
+    * remove `no_std` feature, fixed #19
+* **`0.4.0`**
+    * Re-export `typenum`
+* **`0.3.0`**
+    * Implement `IntoIter` for `GenericArray`
+    * Add `map` method
+    * Add optional `serde` (de)serialization support feature.
+* **`< 0.3.0`**
+    * Initial implementation in late 2015
diff --git a/third_party/rust/generic-array/Cargo.toml b/third_party/rust/generic-array/Cargo.toml
new file mode 100644
index 0000000000..f04fc7bf73
--- /dev/null
+++ b/third_party/rust/generic-array/Cargo.toml
@@ -0,0 +1,75 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+name = "generic-array"
+version = "0.14.6"
+authors = [
+    "Bartłomiej Kamiński <fizyk20@gmail.com>",
+    "Aaron Trent <novacrazy@gmail.com>",
+]
+include = [
+    "src/**/*",
+    "LICENSE",
+    "README.md",
+    "CHANGELOG.md",
+    "build.rs",
+]
+description = "Generic types implementing functionality of arrays"
+documentation = "http://fizyk20.github.io/generic-array/generic_array/"
+readme = "README.md"
+keywords = [
+    "generic",
+    "array",
+]
+categories = [
+    "data-structures",
+    "no-std",
+]
+license = "MIT"
+repository = "https://github.com/fizyk20/generic-array.git"
+
+[package.metadata.docs.rs]
+features = [
+    "serde",
+    "zeroize",
+]
+
+[lib]
+name = "generic_array"
+
+[dependencies.serde]
+version = "1.0"
+optional = true
+default-features = false
+
+[dependencies.typenum]
+version = "1.12"
+
+[dependencies.zeroize]
+version = "1"
+optional = true
+default-features = false
+
+[dev-dependencies.bincode]
+version = "1.0"
+
+[dev-dependencies.serde_json]
+version = "1.0"
+
+[build-dependencies.version_check]
+version = "0.9"
+
+[features]
+more_lengths = []
+
+[badges.travis-ci]
+repository = "fizyk20/generic-array"
diff --git a/third_party/rust/generic-array/LICENSE b/third_party/rust/generic-array/LICENSE
new file mode 100644
index 0000000000..6d318946df
--- /dev/null
+++ b/third_party/rust/generic-array/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Bartłomiej Kamiński
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+\ No newline at end of file
diff --git a/third_party/rust/generic-array/README.md b/third_party/rust/generic-array/README.md
new file mode 100644
index 0000000000..cf54f40550
--- /dev/null
+++ b/third_party/rust/generic-array/README.md
@@ -0,0 +1,62 @@
+[![Crates.io](https://img.shields.io/crates/v/generic-array.svg)](https://crates.io/crates/generic-array)
+[![Build Status](https://travis-ci.org/fizyk20/generic-array.svg?branch=master)](https://travis-ci.org/fizyk20/generic-array)
+# generic-array
+
+This crate implements generic array types for Rust.
+
+**Requires minumum Rust version of 1.36.0, or 1.41.0 for `From<[T; N]>` implementations**
+
+[Documentation](http://fizyk20.github.io/generic-array/generic_array/)
+
+## Usage
+
+The Rust arrays `[T; N]` are problematic in that they can't be used generically with respect to `N`, so for example this won't work:
+
+```rust
+struct Foo<N> {
+	data: [i32; N]
+}
+```
+
+**generic-array** defines a new trait `ArrayLength<T>` and a struct `GenericArray<T, N: ArrayLength<T>>`, which let the above be implemented as:
+
+```rust
+struct Foo<N: ArrayLength<i32>> {
+	data: GenericArray<i32, N>
+}
+```
+
+The `ArrayLength<T>` trait is implemented by default for [unsigned integer types](http://fizyk20.github.io/generic-array/typenum/uint/index.html) from [typenum](http://fizyk20.github.io/generic-array/typenum/index.html) crate:
+
+```rust
+use generic_array::typenum::U5;
+
+struct Foo<N: ArrayLength<i32>> {
+    data: GenericArray<i32, N>
+}
+
+fn main() {
+    let foo = Foo::<U5>{data: GenericArray::default()};
+}
+```
+
+For example, `GenericArray<T, U5>` would work almost like `[T; 5]`:
+
+```rust
+use generic_array::typenum::U5;
+
+struct Foo<T, N: ArrayLength<T>> {
+    data: GenericArray<T, N>
+}
+
+fn main() {
+    let foo = Foo::<i32, U5>{data: GenericArray::default()};
+}
+```
+
+In version 0.1.1 an `arr!` macro was introduced, allowing for creation of arrays as shown below:
+
+```rust
+let array = arr![u32; 1, 2, 3];
+assert_eq!(array[2], 3);
+```
diff --git a/third_party/rust/generic-array/build.rs b/third_party/rust/generic-array/build.rs
new file mode 100644
index 0000000000..c27c7e3fa9
--- /dev/null
+++ b/third_party/rust/generic-array/build.rs
@@ -0,0 +1,5 @@
+fn main() {
+    if version_check::is_min_version("1.41.0").unwrap_or(false) {
+        println!("cargo:rustc-cfg=relaxed_coherence");
+    }
+}
diff --git a/third_party/rust/generic-array/src/arr.rs b/third_party/rust/generic-array/src/arr.rs
new file mode 100644
index 0000000000..cdcc038a3d
--- /dev/null
+++ b/third_party/rust/generic-array/src/arr.rs
@@ -0,0 +1,125 @@
+//! Implementation for `arr!` macro.
+
+use super::ArrayLength;
+use core::ops::Add;
+use typenum::U1;
+
+/// Helper trait for `arr!` macro
+pub trait AddLength<T, N: ArrayLength<T>>: ArrayLength<T> {
+    /// Resulting length
+    type Output: ArrayLength<T>;
+}
+
+impl<T, N1, N2> AddLength<T, N2> for N1
+where
+    N1: ArrayLength<T> + Add<N2>,
+    N2: ArrayLength<T>,
+    <N1 as Add<N2>>::Output: ArrayLength<T>,
+{
+    type Output = <N1 as Add<N2>>::Output;
+}
+
+/// Helper type for `arr!` macro
+pub type Inc<T, U> = <U as AddLength<T, U1>>::Output;
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! arr_impl {
+    (@replace_expr $e:expr) => { 1 };
+    ($T:ty; $N:ty, [$($x:expr),*], []) => ({
+        const __ARR_LENGTH: usize = 0 $(+ $crate::arr_impl!(@replace_expr $x) )*;
+
+        #[inline(always)]
+        fn __do_transmute<T, N: $crate::ArrayLength<T>>(arr: [T; __ARR_LENGTH]) -> $crate::GenericArray<T, N> {
+            unsafe { $crate::transmute(arr) }
+        }
+
+        let _: [(); <$N as $crate::typenum::Unsigned>::USIZE] = [(); __ARR_LENGTH];
+
+        __do_transmute::<$T, $N>([$($x as $T),*])
+    });
+    ($T:ty; $N:ty, [], [$x1:expr]) => (
+        $crate::arr_impl!($T; $crate::arr::Inc<$T, $N>, [$x1], [])
+    );
+    ($T:ty; $N:ty, [], [$x1:expr, $($x:expr),+]) => (
+        $crate::arr_impl!($T; $crate::arr::Inc<$T, $N>, [$x1], [$($x),+])
+    );
+    ($T:ty; $N:ty, [$($y:expr),+], [$x1:expr]) => (
+        $crate::arr_impl!($T; $crate::arr::Inc<$T, $N>, [$($y),+, $x1], [])
+    );
+    ($T:ty; $N:ty, [$($y:expr),+], [$x1:expr, $($x:expr),+]) => (
+        $crate::arr_impl!($T; $crate::arr::Inc<$T, $N>, [$($y),+, $x1], [$($x),+])
+    );
+}
+
+/// Macro allowing for easy generation of Generic Arrays.
+/// Example: `let test = arr![u32; 1, 2, 3];`
+#[macro_export]
+macro_rules! arr {
+    ($T:ty; $(,)*) => ({
+        unsafe { $crate::transmute::<[$T; 0], $crate::GenericArray<$T, $crate::typenum::U0>>([]) }
+    });
+    ($T:ty; $($x:expr),* $(,)*) => (
+        $crate::arr_impl!($T; $crate::typenum::U0, [], [$($x),*])
+    );
+    ($($x:expr,)+) => (arr![$($x),+]);
+    () => ("""Macro requires a type, e.g. `let array = arr![u32; 1, 2, 3];`")
+}
+
+mod doctests_only {
+    ///
+    /// # With ellision
+    ///
+    /// Testing that lifetimes aren't transmuted when they're ellided.
+    ///
+    /// ```compile_fail
+    /// #[macro_use] extern crate generic_array;
+    /// fn main() {
+    ///    fn unsound_lifetime_extension<'a, A>(a: &'a A) -> &'static A {
+    ///        arr![&A; a][0]
+    ///    }
+    /// }
+    /// ```
+    ///
+    /// ```rust
+    /// #[macro_use] extern crate generic_array;
+    /// fn main() {
+    ///    fn unsound_lifetime_extension<'a, A>(a: &'a A) -> &'a A {
+    ///        arr![&A; a][0]
+    ///    }
+    /// }
+    /// ```
+    ///
+    /// # Without ellision
+    ///
+    /// Testing that lifetimes aren't transmuted when they're specified explicitly.
+    ///
+    /// ```compile_fail
+    /// #[macro_use] extern crate generic_array;
+    /// fn main() {
+    ///    fn unsound_lifetime_extension<'a, A>(a: &'a A) -> &'static A {
+    ///        arr![&'a A; a][0]
+    ///    }
+    /// }
+    /// ```
+    ///
+    /// ```compile_fail
+    /// #[macro_use] extern crate generic_array;
+    /// fn main() {
+    ///    fn unsound_lifetime_extension<'a, A>(a: &'a A) -> &'static A {
+    ///        arr![&'static A; a][0]
+    ///    }
+    /// }
+    /// ```
+    ///
+    /// ```rust
+    /// #[macro_use] extern crate generic_array;
+    /// fn main() {
+    ///    fn unsound_lifetime_extension<'a, A>(a: &'a A) -> &'a A {
+    ///        arr![&'a A; a][0]
+    ///    }
+    /// }
+    /// ```
+    #[allow(dead_code)]
+    pub enum DocTests {}
+}
diff --git a/third_party/rust/generic-array/src/functional.rs b/third_party/rust/generic-array/src/functional.rs
new file mode 100644
index 0000000000..2ddcc5c4c4
--- /dev/null
+++ b/third_party/rust/generic-array/src/functional.rs
@@ -0,0 +1,95 @@
+//! Functional programming with generic sequences
+//!
+//! Please see `tests/generics.rs` for examples of how to best use these in your generic functions.
+
+use super::ArrayLength;
+use core::iter::FromIterator;
+
+use crate::sequence::*;
+
+/// Defines the relationship between one generic sequence and another,
+/// for operations such as `map` and `zip`.
+pub unsafe trait MappedGenericSequence<T, U>: GenericSequence<T>
+where
+    Self::Length: ArrayLength<U>,
+{
+    /// Mapped sequence type
+    type Mapped: GenericSequence<U, Length = Self::Length>;
+}
+
+unsafe impl<'a, T, U, S: MappedGenericSequence<T, U>> MappedGenericSequence<T, U> for &'a S
+where
+    &'a S: GenericSequence<T>,
+    S: GenericSequence<T, Length = <&'a S as GenericSequence<T>>::Length>,
+    <S as GenericSequence<T>>::Length: ArrayLength<U>,
+{
+    type Mapped = <S as MappedGenericSequence<T, U>>::Mapped;
+}
+
+unsafe impl<'a, T, U, S: MappedGenericSequence<T, U>> MappedGenericSequence<T, U> for &'a mut S
+where
+    &'a mut S: GenericSequence<T>,
+    S: GenericSequence<T, Length = <&'a mut S as GenericSequence<T>>::Length>,
+    <S as GenericSequence<T>>::Length: ArrayLength<U>,
+{
+    type Mapped = <S as MappedGenericSequence<T, U>>::Mapped;
+}
+
+/// Accessor type for a mapped generic sequence
+pub type MappedSequence<S, T, U> =
+    <<S as MappedGenericSequence<T, U>>::Mapped as GenericSequence<U>>::Sequence;
+
+/// Defines functional programming methods for generic sequences
+pub unsafe trait FunctionalSequence<T>: GenericSequence<T> {
+    /// Maps a `GenericSequence` to another `GenericSequence`.
+    ///
+    /// If the mapping function panics, any already initialized elements in the new sequence
+    /// will be dropped, AND any unused elements in the source sequence will also be dropped.
+    fn map<U, F>(self, f: F) -> MappedSequence<Self, T, U>
+    where
+        Self: MappedGenericSequence<T, U>,
+        Self::Length: ArrayLength<U>,
+        F: FnMut(Self::Item) -> U,
+    {
+        FromIterator::from_iter(self.into_iter().map(f))
+    }
+
+    /// Combines two `GenericSequence` instances and iterates through both of them,
+    /// initializing a new `GenericSequence` with the result of the zipped mapping function.
+    ///
+    /// If the mapping function panics, any already initialized elements in the new sequence
+    /// will be dropped, AND any unused elements in the source sequences will also be dropped.
+    #[inline]
+    fn zip<B, Rhs, U, F>(self, rhs: Rhs, f: F) -> MappedSequence<Self, T, U>
+    where
+        Self: MappedGenericSequence<T, U>,
+        Rhs: MappedGenericSequence<B, U, Mapped = MappedSequence<Self, T, U>>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        Rhs: GenericSequence<B, Length = Self::Length>,
+        F: FnMut(Self::Item, Rhs::Item) -> U,
+    {
+        rhs.inverted_zip2(self, f)
+    }
+
+    /// Folds (or reduces) a sequence of data into a single value.
+    ///
+    /// If the fold function panics, any unused elements will be dropped.
+    fn fold<U, F>(self, init: U, f: F) -> U
+    where
+        F: FnMut(U, Self::Item) -> U,
+    {
+        self.into_iter().fold(init, f)
+    }
+}
+
+unsafe impl<'a, T, S: GenericSequence<T>> FunctionalSequence<T> for &'a S
+where
+    &'a S: GenericSequence<T>,
+{
+}
+
+unsafe impl<'a, T, S: GenericSequence<T>> FunctionalSequence<T> for &'a mut S
+where
+    &'a mut S: GenericSequence<T>,
+{
+}
diff --git a/third_party/rust/generic-array/src/hex.rs b/third_party/rust/generic-array/src/hex.rs
new file mode 100644
index 0000000000..33c796f3c9
--- /dev/null
+++ b/third_party/rust/generic-array/src/hex.rs
@@ -0,0 +1,105 @@
+//! Generic array are commonly used as a return value for hash digests, so
+//! it's a good idea to allow to hexlify them easily. This module implements
+//! `std::fmt::LowerHex` and `std::fmt::UpperHex` traits.
+//!
+//! Example:
+//!
+//! ```rust
+//! # #[macro_use]
+//! # extern crate generic_array;
+//! # extern crate typenum;
+//! # fn main() {
+//! let array = arr![u8; 10, 20, 30];
+//! assert_eq!(format!("{:x}", array), "0a141e");
+//! # }
+//! ```
+//!
+
+use core::{fmt, str, ops::Add, cmp::min};
+
+use typenum::*;
+
+use crate::{ArrayLength, GenericArray};
+
+static LOWER_CHARS: &'static [u8] = b"0123456789abcdef";
+static UPPER_CHARS: &'static [u8] = b"0123456789ABCDEF";
+
+impl<T: ArrayLength<u8>> fmt::LowerHex for GenericArray<u8, T>
+where
+    T: Add<T>,
+    <T as Add<T>>::Output: ArrayLength<u8>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let max_digits = f.precision().unwrap_or_else(|| self.len() * 2);
+        let max_hex = (max_digits >> 1) + (max_digits & 1);
+
+        if T::USIZE < 1024 {
+            // For small arrays use a stack allocated
+            // buffer of 2x number of bytes
+            let mut res = GenericArray::<u8, Sum<T, T>>::default();
+
+            self.iter().take(max_hex).enumerate().for_each(|(i, c)| {
+                res[i * 2] = LOWER_CHARS[(c >> 4) as usize];
+                res[i * 2 + 1] = LOWER_CHARS[(c & 0xF) as usize];
+            });
+
+            f.write_str(unsafe { str::from_utf8_unchecked(&res[..max_digits]) })?;
+        } else {
+            // For large array use chunks of up to 1024 bytes (2048 hex chars)
+            let mut buf = [0u8; 2048];
+            let mut digits_left = max_digits;
+
+            for chunk in self[..max_hex].chunks(1024) {
+                chunk.iter().enumerate().for_each(|(i, c)| {
+                    buf[i * 2] = LOWER_CHARS[(c >> 4) as usize];
+                    buf[i * 2 + 1] = LOWER_CHARS[(c & 0xF) as usize];
+                });
+
+                let n = min(chunk.len() * 2, digits_left);
+                f.write_str(unsafe { str::from_utf8_unchecked(&buf[..n]) })?;
+                digits_left -= n;
+            }
+        }
+        Ok(())
+    }
+}
+
+impl<T: ArrayLength<u8>> fmt::UpperHex for GenericArray<u8, T>
+where
+    T: Add<T>,
+    <T as Add<T>>::Output: ArrayLength<u8>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let max_digits = f.precision().unwrap_or_else(|| self.len() * 2);
+        let max_hex = (max_digits >> 1) + (max_digits & 1);
+
+        if T::USIZE < 1024 {
+            // For small arrays use a stack allocated
+            // buffer of 2x number of bytes
+            let mut res = GenericArray::<u8, Sum<T, T>>::default();
+
+            self.iter().take(max_hex).enumerate().for_each(|(i, c)| {
+                res[i * 2] = UPPER_CHARS[(c >> 4) as usize];
+                res[i * 2 + 1] = UPPER_CHARS[(c & 0xF) as usize];
+            });
+
+            f.write_str(unsafe { str::from_utf8_unchecked(&res[..max_digits]) })?;
+        } else {
+            // For large array use chunks of up to 1024 bytes (2048 hex chars)
+            let mut buf = [0u8; 2048];
+            let mut digits_left = max_digits;
+
+            for chunk in self[..max_hex].chunks(1024) {
+                chunk.iter().enumerate().for_each(|(i, c)| {
+                    buf[i * 2] = UPPER_CHARS[(c >> 4) as usize];
+                    buf[i * 2 + 1] = UPPER_CHARS[(c & 0xF) as usize];
+                });
+
+                let n = min(chunk.len() * 2, digits_left);
+                f.write_str(unsafe { str::from_utf8_unchecked(&buf[..n]) })?;
+                digits_left -= n;
+            }
+        }
+        Ok(())
+    }
+}
diff --git a/third_party/rust/generic-array/src/impl_serde.rs b/third_party/rust/generic-array/src/impl_serde.rs
new file mode 100644
index 0000000000..49c095a5de
--- /dev/null
+++ b/third_party/rust/generic-array/src/impl_serde.rs
@@ -0,0 +1,108 @@
+//! Serde serialization/deserialization implementation
+
+use core::fmt;
+use core::marker::PhantomData;
+use serde::de::{self, SeqAccess, Visitor};
+use serde::{ser::SerializeTuple, Deserialize, Deserializer, Serialize, Serializer};
+use {ArrayLength, GenericArray};
+
+impl<T, N> Serialize for GenericArray<T, N>
+where
+    T: Serialize,
+    N: ArrayLength<T>,
+{
+    #[inline]
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut tup = serializer.serialize_tuple(N::USIZE)?;
+        for el in self {
+            tup.serialize_element(el)?;
+        }
+
+        tup.end()
+    }
+}
+
+struct GAVisitor<T, N> {
+    _t: PhantomData<T>,
+    _n: PhantomData<N>,
+}
+
+impl<'de, T, N> Visitor<'de> for GAVisitor<T, N>
+where
+    T: Deserialize<'de> + Default,
+    N: ArrayLength<T>,
+{
+    type Value = GenericArray<T, N>;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("struct GenericArray")
+    }
+
+    fn visit_seq<A>(self, mut seq: A) -> Result<GenericArray<T, N>, A::Error>
+    where
+        A: SeqAccess<'de>,
+    {
+        let mut result = GenericArray::default();
+        for i in 0..N::USIZE {
+            result[i] = seq
+                .next_element()?
+                .ok_or_else(|| de::Error::invalid_length(i, &self))?;
+        }
+        Ok(result)
+    }
+}
+
+impl<'de, T, N> Deserialize<'de> for GenericArray<T, N>
+where
+    T: Deserialize<'de> + Default,
+    N: ArrayLength<T>,
+{
+    fn deserialize<D>(deserializer: D) -> Result<GenericArray<T, N>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let visitor = GAVisitor {
+            _t: PhantomData,
+            _n: PhantomData,
+        };
+        deserializer.deserialize_tuple(N::USIZE, visitor)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use bincode;
+    use typenum;
+
+    #[test]
+    fn test_serialize() {
+        let array = GenericArray::<u8, typenum::U2>::default();
+        let serialized = bincode::serialize(&array);
+        assert!(serialized.is_ok());
+    }
+
+    #[test]
+    fn test_deserialize() {
+        let mut array = GenericArray::<u8, typenum::U2>::default();
+        array[0] = 1;
+        array[1] = 2;
+        let serialized = bincode::serialize(&array).unwrap();
+        let deserialized = bincode::deserialize::<GenericArray<u8, typenum::U2>>(&serialized);
+        assert!(deserialized.is_ok());
+        let array = deserialized.unwrap();
+        assert_eq!(array[0], 1);
+        assert_eq!(array[1], 2);
+    }
+
+    #[test]
+    fn test_serialized_size() {
+        let array = GenericArray::<u8, typenum::U1>::default();
+        let size = bincode::serialized_size(&array).unwrap();
+        assert_eq!(size, 1);
+    }
+
+}
diff --git a/third_party/rust/generic-array/src/impl_zeroize.rs b/third_party/rust/generic-array/src/impl_zeroize.rs
new file mode 100644
index 0000000000..9937e4b150
--- /dev/null
+++ b/third_party/rust/generic-array/src/impl_zeroize.rs
@@ -0,0 +1,25 @@
+use {ArrayLength, GenericArray};
+
+use zeroize::Zeroize;
+
+#[cfg_attr(docsrs, doc(cfg(feature = "zeroize")))]
+impl<T: Zeroize, N: ArrayLength<T>> Zeroize for GenericArray<T, N> {
+    fn zeroize(&mut self) {
+        self.as_mut_slice().iter_mut().zeroize()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_zeroize() {
+        let mut array = GenericArray::<u8, typenum::U2>::default();
+        array[0] = 4;
+        array[1] = 9;
+        array.zeroize();
+        assert_eq!(array[0], 0);
+        assert_eq!(array[1], 0);
+    }
+}
+\ No newline at end of file
diff --git a/third_party/rust/generic-array/src/impls.rs b/third_party/rust/generic-array/src/impls.rs
new file mode 100644
index 0000000000..47ecc1d31d
--- /dev/null
+++ b/third_party/rust/generic-array/src/impls.rs
@@ -0,0 +1,269 @@
+use core::borrow::{Borrow, BorrowMut};
+use core::cmp::Ordering;
+use core::fmt::{self, Debug};
+use core::hash::{Hash, Hasher};
+
+use super::{ArrayLength, GenericArray};
+
+use crate::functional::*;
+use crate::sequence::*;
+
+impl<T: Default, N> Default for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn default() -> Self {
+        Self::generate(|_| T::default())
+    }
+}
+
+impl<T: Clone, N> Clone for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn clone(&self) -> GenericArray<T, N> {
+        self.map(Clone::clone)
+    }
+}
+
+impl<T: Copy, N> Copy for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    N::ArrayType: Copy,
+{
+}
+
+impl<T: PartialEq, N> PartialEq for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn eq(&self, other: &Self) -> bool {
+        **self == **other
+    }
+}
+impl<T: Eq, N> Eq for GenericArray<T, N> where N: ArrayLength<T> {}
+
+impl<T: PartialOrd, N> PartialOrd for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn partial_cmp(&self, other: &GenericArray<T, N>) -> Option<Ordering> {
+        PartialOrd::partial_cmp(self.as_slice(), other.as_slice())
+    }
+}
+
+impl<T: Ord, N> Ord for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn cmp(&self, other: &GenericArray<T, N>) -> Ordering {
+        Ord::cmp(self.as_slice(), other.as_slice())
+    }
+}
+
+impl<T: Debug, N> Debug for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        self[..].fmt(fmt)
+    }
+}
+
+impl<T, N> Borrow<[T]> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn borrow(&self) -> &[T] {
+        &self[..]
+    }
+}
+
+impl<T, N> BorrowMut<[T]> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn borrow_mut(&mut self) -> &mut [T] {
+        &mut self[..]
+    }
+}
+
+impl<T, N> AsRef<[T]> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn as_ref(&self) -> &[T] {
+        &self[..]
+    }
+}
+
+impl<T, N> AsMut<[T]> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn as_mut(&mut self) -> &mut [T] {
+        &mut self[..]
+    }
+}
+
+impl<T: Hash, N> Hash for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: Hasher,
+    {
+        Hash::hash(&self[..], state)
+    }
+}
+
+macro_rules! impl_from {
+    ($($n: expr => $ty: ty),*) => {
+        $(
+            impl<T> From<[T; $n]> for GenericArray<T, $ty> {
+                #[inline(always)]
+                fn from(arr: [T; $n]) -> Self {
+                    unsafe { $crate::transmute(arr) }
+                }
+            }
+
+            #[cfg(relaxed_coherence)]
+            impl<T> From<GenericArray<T, $ty>> for [T; $n] {
+                #[inline(always)]
+                fn from(sel: GenericArray<T, $ty>) -> [T; $n] {
+                    unsafe { $crate::transmute(sel) }
+                }
+            }
+
+            impl<'a, T> From<&'a [T; $n]> for &'a GenericArray<T, $ty> {
+                #[inline]
+                fn from(slice: &[T; $n]) -> &GenericArray<T, $ty> {
+                    unsafe { &*(slice.as_ptr() as *const GenericArray<T, $ty>) }
+                }
+            }
+
+            impl<'a, T> From<&'a mut [T; $n]> for &'a mut GenericArray<T, $ty> {
+                #[inline]
+                fn from(slice: &mut [T; $n]) -> &mut GenericArray<T, $ty> {
+                    unsafe { &mut *(slice.as_mut_ptr() as *mut GenericArray<T, $ty>) }
+                }
+            }
+
+            #[cfg(not(relaxed_coherence))]
+            impl<T> Into<[T; $n]> for GenericArray<T, $ty> {
+                #[inline(always)]
+                fn into(self) -> [T; $n] {
+                    unsafe { $crate::transmute(self) }
+                }
+            }
+
+            impl<T> AsRef<[T; $n]> for GenericArray<T, $ty> {
+                #[inline]
+                fn as_ref(&self) -> &[T; $n] {
+                    unsafe { $crate::transmute(self) }
+                }
+            }
+
+            impl<T> AsMut<[T; $n]> for GenericArray<T, $ty> {
+                #[inline]
+                fn as_mut(&mut self) -> &mut [T; $n] {
+                    unsafe { $crate::transmute(self) }
+                }
+            }
+        )*
+    }
+}
+
+impl_from! {
+    1  => ::typenum::U1,
+    2  => ::typenum::U2,
+    3  => ::typenum::U3,
+    4  => ::typenum::U4,
+    5  => ::typenum::U5,
+    6  => ::typenum::U6,
+    7  => ::typenum::U7,
+    8  => ::typenum::U8,
+    9  => ::typenum::U9,
+    10 => ::typenum::U10,
+    11 => ::typenum::U11,
+    12 => ::typenum::U12,
+    13 => ::typenum::U13,
+    14 => ::typenum::U14,
+    15 => ::typenum::U15,
+    16 => ::typenum::U16,
+    17 => ::typenum::U17,
+    18 => ::typenum::U18,
+    19 => ::typenum::U19,
+    20 => ::typenum::U20,
+    21 => ::typenum::U21,
+    22 => ::typenum::U22,
+    23 => ::typenum::U23,
+    24 => ::typenum::U24,
+    25 => ::typenum::U25,
+    26 => ::typenum::U26,
+    27 => ::typenum::U27,
+    28 => ::typenum::U28,
+    29 => ::typenum::U29,
+    30 => ::typenum::U30,
+    31 => ::typenum::U31,
+    32 => ::typenum::U32
+}
+
+#[cfg(feature = "more_lengths")]
+impl_from! {
+    33 => ::typenum::U33,
+    34 => ::typenum::U34,
+    35 => ::typenum::U35,
+    36 => ::typenum::U36,
+    37 => ::typenum::U37,
+    38 => ::typenum::U38,
+    39 => ::typenum::U39,
+    40 => ::typenum::U40,
+    41 => ::typenum::U41,
+    42 => ::typenum::U42,
+    43 => ::typenum::U43,
+    44 => ::typenum::U44,
+    45 => ::typenum::U45,
+    46 => ::typenum::U46,
+    47 => ::typenum::U47,
+    48 => ::typenum::U48,
+    49 => ::typenum::U49,
+    50 => ::typenum::U50,
+    51 => ::typenum::U51,
+    52 => ::typenum::U52,
+    53 => ::typenum::U53,
+    54 => ::typenum::U54,
+    55 => ::typenum::U55,
+    56 => ::typenum::U56,
+    57 => ::typenum::U57,
+    58 => ::typenum::U58,
+    59 => ::typenum::U59,
+    60 => ::typenum::U60,
+    61 => ::typenum::U61,
+    62 => ::typenum::U62,
+    63 => ::typenum::U63,
+    64 => ::typenum::U64,
+
+    70 => ::typenum::U70,
+    80 => ::typenum::U80,
+    90 => ::typenum::U90,
+
+    100 => ::typenum::U100,
+    200 => ::typenum::U200,
+    300 => ::typenum::U300,
+    400 => ::typenum::U400,
+    500 => ::typenum::U500,
+
+    128 => ::typenum::U128,
+    256 => ::typenum::U256,
+    512 => ::typenum::U512,
+
+    1000 => ::typenum::U1000,
+    1024 => ::typenum::U1024
+}
diff --git a/third_party/rust/generic-array/src/iter.rs b/third_party/rust/generic-array/src/iter.rs
new file mode 100644
index 0000000000..784ffa9068
--- /dev/null
+++ b/third_party/rust/generic-array/src/iter.rs
@@ -0,0 +1,251 @@
+//! `GenericArray` iterator implementation.
+
+use super::{ArrayLength, GenericArray};
+use core::iter::FusedIterator;
+use core::mem::ManuallyDrop;
+use core::{cmp, fmt, mem, ptr};
+
+/// An iterator that moves out of a `GenericArray`
+pub struct GenericArrayIter<T, N: ArrayLength<T>> {
+    // Invariants: index <= index_back <= N
+    // Only values in array[index..index_back] are alive at any given time.
+    // Values from array[..index] and array[index_back..] are already moved/dropped.
+    array: ManuallyDrop<GenericArray<T, N>>,
+    index: usize,
+    index_back: usize,
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    fn send<I: Send>(_iter: I) {}
+
+    #[test]
+    fn test_send_iter() {
+        send(GenericArray::from([1, 2, 3, 4]).into_iter());
+    }
+}
+
+impl<T, N> GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    /// Returns the remaining items of this iterator as a slice
+    #[inline]
+    pub fn as_slice(&self) -> &[T] {
+        &self.array.as_slice()[self.index..self.index_back]
+    }
+
+    /// Returns the remaining items of this iterator as a mutable slice
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut [T] {
+        &mut self.array.as_mut_slice()[self.index..self.index_back]
+    }
+}
+
+impl<T, N> IntoIterator for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    type Item = T;
+    type IntoIter = GenericArrayIter<T, N>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        GenericArrayIter {
+            array: ManuallyDrop::new(self),
+            index: 0,
+            index_back: N::USIZE,
+        }
+    }
+}
+
+// Based on work in rust-lang/rust#49000
+impl<T: fmt::Debug, N> fmt::Debug for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("GenericArrayIter")
+            .field(&self.as_slice())
+            .finish()
+    }
+}
+
+impl<T, N> Drop for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline]
+    fn drop(&mut self) {
+        if mem::needs_drop::<T>() {
+            // Drop values that are still alive.
+            for p in self.as_mut_slice() {
+                unsafe {
+                    ptr::drop_in_place(p);
+                }
+            }
+        }
+    }
+}
+
+// Based on work in rust-lang/rust#49000
+impl<T: Clone, N> Clone for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn clone(&self) -> Self {
+        // This places all cloned elements at the start of the new array iterator,
+        // not at their original indices.
+
+        let mut array = unsafe { ptr::read(&self.array) };
+        let mut index_back = 0;
+
+        for (dst, src) in array.as_mut_slice().into_iter().zip(self.as_slice()) {
+            unsafe { ptr::write(dst, src.clone()) };
+            index_back += 1;
+        }
+
+        GenericArrayIter {
+            array,
+            index: 0,
+            index_back,
+        }
+    }
+}
+
+impl<T, N> Iterator for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    type Item = T;
+
+    #[inline]
+    fn next(&mut self) -> Option<T> {
+        if self.index < self.index_back {
+            let p = unsafe { Some(ptr::read(self.array.get_unchecked(self.index))) };
+
+            self.index += 1;
+
+            p
+        } else {
+            None
+        }
+    }
+
+    fn fold<B, F>(mut self, init: B, mut f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        let ret = unsafe {
+            let GenericArrayIter {
+                ref array,
+                ref mut index,
+                index_back,
+            } = self;
+
+            let remaining = &array[*index..index_back];
+
+            remaining.iter().fold(init, |acc, src| {
+                let value = ptr::read(src);
+
+                *index += 1;
+
+                f(acc, value)
+            })
+        };
+
+        // ensure the drop happens here after iteration
+        drop(self);
+
+        ret
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.len();
+        (len, Some(len))
+    }
+
+    #[inline]
+    fn count(self) -> usize {
+        self.len()
+    }
+
+    fn nth(&mut self, n: usize) -> Option<T> {
+        // First consume values prior to the nth.
+        let ndrop = cmp::min(n, self.len());
+
+        for p in &mut self.array[self.index..self.index + ndrop] {
+            self.index += 1;
+
+            unsafe {
+                ptr::drop_in_place(p);
+            }
+        }
+
+        self.next()
+    }
+
+    #[inline]
+    fn last(mut self) -> Option<T> {
+        // Note, everything else will correctly drop first as `self` leaves scope.
+        self.next_back()
+    }
+}
+
+impl<T, N> DoubleEndedIterator for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn next_back(&mut self) -> Option<T> {
+        if self.index < self.index_back {
+            self.index_back -= 1;
+
+            unsafe { Some(ptr::read(self.array.get_unchecked(self.index_back))) }
+        } else {
+            None
+        }
+    }
+
+    fn rfold<B, F>(mut self, init: B, mut f: F) -> B
+    where
+        F: FnMut(B, Self::Item) -> B,
+    {
+        let ret = unsafe {
+            let GenericArrayIter {
+                ref array,
+                index,
+                ref mut index_back,
+            } = self;
+
+            let remaining = &array[index..*index_back];
+
+            remaining.iter().rfold(init, |acc, src| {
+                let value = ptr::read(src);
+
+                *index_back -= 1;
+
+                f(acc, value)
+            })
+        };
+
+        // ensure the drop happens here after iteration
+        drop(self);
+
+        ret
+    }
+}
+
+impl<T, N> ExactSizeIterator for GenericArrayIter<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn len(&self) -> usize {
+        self.index_back - self.index
+    }
+}
+
+impl<T, N> FusedIterator for GenericArrayIter<T, N> where N: ArrayLength<T> {}
+
+// TODO: Implement `TrustedLen` when stabilized
diff --git a/third_party/rust/generic-array/src/lib.rs b/third_party/rust/generic-array/src/lib.rs
new file mode 100644
index 0000000000..43ab26ff56
--- /dev/null
+++ b/third_party/rust/generic-array/src/lib.rs
@@ -0,0 +1,679 @@
+//! This crate implements a structure that can be used as a generic array type.
+//! Core Rust array types `[T; N]` can't be used generically with
+//! respect to `N`, so for example this:
+//!
+//! ```rust{compile_fail}
+//! struct Foo<T, N> {
+//!     data: [T; N]
+//! }
+//! ```
+//!
+//! won't work.
+//!
+//! **generic-array** exports a `GenericArray<T,N>` type, which lets
+//! the above be implemented as:
+//!
+//! ```rust
+//! use generic_array::{ArrayLength, GenericArray};
+//!
+//! struct Foo<T, N: ArrayLength<T>> {
+//!     data: GenericArray<T,N>
+//! }
+//! ```
+//!
+//! The `ArrayLength<T>` trait is implemented by default for
+//! [unsigned integer types](../typenum/uint/index.html) from
+//! [typenum](../typenum/index.html):
+//!
+//! ```rust
+//! # use generic_array::{ArrayLength, GenericArray};
+//! use generic_array::typenum::U5;
+//!
+//! struct Foo<N: ArrayLength<i32>> {
+//!     data: GenericArray<i32, N>
+//! }
+//!
+//! # fn main() {
+//! let foo = Foo::<U5>{data: GenericArray::default()};
+//! # }
+//! ```
+//!
+//! For example, `GenericArray<T, U5>` would work almost like `[T; 5]`:
+//!
+//! ```rust
+//! # use generic_array::{ArrayLength, GenericArray};
+//! use generic_array::typenum::U5;
+//!
+//! struct Foo<T, N: ArrayLength<T>> {
+//!     data: GenericArray<T, N>
+//! }
+//!
+//! # fn main() {
+//! let foo = Foo::<i32, U5>{data: GenericArray::default()};
+//! # }
+//! ```
+//!
+//! For ease of use, an `arr!` macro is provided - example below:
+//!
+//! ```
+//! # #[macro_use]
+//! # extern crate generic_array;
+//! # extern crate typenum;
+//! # fn main() {
+//! let array = arr![u32; 1, 2, 3];
+//! assert_eq!(array[2], 3);
+//! # }
+//! ```
+
+#![deny(missing_docs)]
+#![deny(meta_variable_misuse)]
+#![no_std]
+
+#[cfg(feature = "serde")]
+extern crate serde;
+
+#[cfg(feature = "zeroize")]
+extern crate zeroize;
+
+#[cfg(test)]
+extern crate bincode;
+
+pub extern crate typenum;
+
+mod hex;
+mod impls;
+
+#[cfg(feature = "serde")]
+mod impl_serde;
+
+#[cfg(feature = "zeroize")]
+mod impl_zeroize;
+
+use core::iter::FromIterator;
+use core::marker::PhantomData;
+use core::mem::{MaybeUninit, ManuallyDrop};
+use core::ops::{Deref, DerefMut};
+use core::{mem, ptr, slice};
+use typenum::bit::{B0, B1};
+use typenum::uint::{UInt, UTerm, Unsigned};
+
+#[cfg_attr(test, macro_use)]
+pub mod arr;
+pub mod functional;
+pub mod iter;
+pub mod sequence;
+
+use self::functional::*;
+pub use self::iter::GenericArrayIter;
+use self::sequence::*;
+
+/// Trait making `GenericArray` work, marking types to be used as length of an array
+pub unsafe trait ArrayLength<T>: Unsigned {
+    /// Associated type representing the array type for the number
+    type ArrayType;
+}
+
+unsafe impl<T> ArrayLength<T> for UTerm {
+    #[doc(hidden)]
+    type ArrayType = [T; 0];
+}
+
+/// Internal type used to generate a struct of appropriate size
+#[allow(dead_code)]
+#[repr(C)]
+#[doc(hidden)]
+pub struct GenericArrayImplEven<T, U> {
+    parent1: U,
+    parent2: U,
+    _marker: PhantomData<T>,
+}
+
+impl<T: Clone, U: Clone> Clone for GenericArrayImplEven<T, U> {
+    fn clone(&self) -> GenericArrayImplEven<T, U> {
+        GenericArrayImplEven {
+            parent1: self.parent1.clone(),
+            parent2: self.parent2.clone(),
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl<T: Copy, U: Copy> Copy for GenericArrayImplEven<T, U> {}
+
+/// Internal type used to generate a struct of appropriate size
+#[allow(dead_code)]
+#[repr(C)]
+#[doc(hidden)]
+pub struct GenericArrayImplOdd<T, U> {
+    parent1: U,
+    parent2: U,
+    data: T,
+}
+
+impl<T: Clone, U: Clone> Clone for GenericArrayImplOdd<T, U> {
+    fn clone(&self) -> GenericArrayImplOdd<T, U> {
+        GenericArrayImplOdd {
+            parent1: self.parent1.clone(),
+            parent2: self.parent2.clone(),
+            data: self.data.clone(),
+        }
+    }
+}
+
+impl<T: Copy, U: Copy> Copy for GenericArrayImplOdd<T, U> {}
+
+unsafe impl<T, N: ArrayLength<T>> ArrayLength<T> for UInt<N, B0> {
+    #[doc(hidden)]
+    type ArrayType = GenericArrayImplEven<T, N::ArrayType>;
+}
+
+unsafe impl<T, N: ArrayLength<T>> ArrayLength<T> for UInt<N, B1> {
+    #[doc(hidden)]
+    type ArrayType = GenericArrayImplOdd<T, N::ArrayType>;
+}
+
+/// Struct representing a generic array - `GenericArray<T, N>` works like [T; N]
+#[allow(dead_code)]
+#[repr(transparent)]
+pub struct GenericArray<T, U: ArrayLength<T>> {
+    data: U::ArrayType,
+}
+
+unsafe impl<T: Send, N: ArrayLength<T>> Send for GenericArray<T, N> {}
+unsafe impl<T: Sync, N: ArrayLength<T>> Sync for GenericArray<T, N> {}
+
+impl<T, N> Deref for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    type Target = [T];
+
+    #[inline(always)]
+    fn deref(&self) -> &[T] {
+        unsafe { slice::from_raw_parts(self as *const Self as *const T, N::USIZE) }
+    }
+}
+
+impl<T, N> DerefMut for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    #[inline(always)]
+    fn deref_mut(&mut self) -> &mut [T] {
+        unsafe { slice::from_raw_parts_mut(self as *mut Self as *mut T, N::USIZE) }
+    }
+}
+
+/// Creates an array one element at a time using a mutable iterator
+/// you can write to with `ptr::write`.
+///
+/// Increment the position while iterating to mark off created elements,
+/// which will be dropped if `into_inner` is not called.
+#[doc(hidden)]
+pub struct ArrayBuilder<T, N: ArrayLength<T>> {
+    array: MaybeUninit<GenericArray<T, N>>,
+    position: usize,
+}
+
+impl<T, N: ArrayLength<T>> ArrayBuilder<T, N> {
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new() -> ArrayBuilder<T, N> {
+        ArrayBuilder {
+            array: MaybeUninit::uninit(),
+            position: 0,
+        }
+    }
+
+    /// Creates a mutable iterator for writing to the array using `ptr::write`.
+    ///
+    /// Increment the position value given as a mutable reference as you iterate
+    /// to mark how many elements have been created.
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn iter_position(&mut self) -> (slice::IterMut<T>, &mut usize) {
+        ((&mut *self.array.as_mut_ptr()).iter_mut(), &mut self.position)
+    }
+
+    /// When done writing (assuming all elements have been written to),
+    /// get the inner array.
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn into_inner(self) -> GenericArray<T, N> {
+        let array = ptr::read(&self.array);
+
+        mem::forget(self);
+
+        array.assume_init()
+    }
+}
+
+impl<T, N: ArrayLength<T>> Drop for ArrayBuilder<T, N> {
+    fn drop(&mut self) {
+        if mem::needs_drop::<T>() {
+            unsafe {
+                for value in &mut (&mut *self.array.as_mut_ptr())[..self.position] {
+                    ptr::drop_in_place(value);
+                }
+            }
+        }
+    }
+}
+
+/// Consumes an array.
+///
+/// Increment the position while iterating and any leftover elements
+/// will be dropped if position does not go to N
+#[doc(hidden)]
+pub struct ArrayConsumer<T, N: ArrayLength<T>> {
+    array: ManuallyDrop<GenericArray<T, N>>,
+    position: usize,
+}
+
+impl<T, N: ArrayLength<T>> ArrayConsumer<T, N> {
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn new(array: GenericArray<T, N>) -> ArrayConsumer<T, N> {
+        ArrayConsumer {
+            array: ManuallyDrop::new(array),
+            position: 0,
+        }
+    }
+
+    /// Creates an iterator and mutable reference to the internal position
+    /// to keep track of consumed elements.
+    ///
+    /// Increment the position as you iterate to mark off consumed elements
+    #[doc(hidden)]
+    #[inline]
+    pub unsafe fn iter_position(&mut self) -> (slice::Iter<T>, &mut usize) {
+        (self.array.iter(), &mut self.position)
+    }
+}
+
+impl<T, N: ArrayLength<T>> Drop for ArrayConsumer<T, N> {
+    fn drop(&mut self) {
+        if mem::needs_drop::<T>() {
+            for value in &mut self.array[self.position..N::USIZE] {
+                unsafe {
+                    ptr::drop_in_place(value);
+                }
+            }
+        }
+    }
+}
+
+impl<'a, T: 'a, N> IntoIterator for &'a GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    type IntoIter = slice::Iter<'a, T>;
+    type Item = &'a T;
+
+    fn into_iter(self: &'a GenericArray<T, N>) -> Self::IntoIter {
+        self.as_slice().iter()
+    }
+}
+
+impl<'a, T: 'a, N> IntoIterator for &'a mut GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    type IntoIter = slice::IterMut<'a, T>;
+    type Item = &'a mut T;
+
+    fn into_iter(self: &'a mut GenericArray<T, N>) -> Self::IntoIter {
+        self.as_mut_slice().iter_mut()
+    }
+}
+
+impl<T, N> FromIterator<T> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    fn from_iter<I>(iter: I) -> GenericArray<T, N>
+    where
+        I: IntoIterator<Item = T>,
+    {
+        unsafe {
+            let mut destination = ArrayBuilder::new();
+
+            {
+                let (destination_iter, position) = destination.iter_position();
+
+                iter.into_iter()
+                    .zip(destination_iter)
+                    .for_each(|(src, dst)| {
+                        ptr::write(dst, src);
+
+                        *position += 1;
+                    });
+            }
+
+            if destination.position < N::USIZE {
+                from_iter_length_fail(destination.position, N::USIZE);
+            }
+
+            destination.into_inner()
+        }
+    }
+}
+
+#[inline(never)]
+#[cold]
+fn from_iter_length_fail(length: usize, expected: usize) -> ! {
+    panic!(
+        "GenericArray::from_iter received {} elements but expected {}",
+        length, expected
+    );
+}
+
+unsafe impl<T, N> GenericSequence<T> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    Self: IntoIterator<Item = T>,
+{
+    type Length = N;
+    type Sequence = Self;
+
+    fn generate<F>(mut f: F) -> GenericArray<T, N>
+    where
+        F: FnMut(usize) -> T,
+    {
+        unsafe {
+            let mut destination = ArrayBuilder::new();
+
+            {
+                let (destination_iter, position) = destination.iter_position();
+
+                destination_iter.enumerate().for_each(|(i, dst)| {
+                    ptr::write(dst, f(i));
+
+                    *position += 1;
+                });
+            }
+
+            destination.into_inner()
+        }
+    }
+
+    #[doc(hidden)]
+    fn inverted_zip<B, U, F>(
+        self,
+        lhs: GenericArray<B, Self::Length>,
+        mut f: F,
+    ) -> MappedSequence<GenericArray<B, Self::Length>, B, U>
+    where
+        GenericArray<B, Self::Length>:
+            GenericSequence<B, Length = Self::Length> + MappedGenericSequence<B, U>,
+        Self: MappedGenericSequence<T, U>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        F: FnMut(B, Self::Item) -> U,
+    {
+        unsafe {
+            let mut left = ArrayConsumer::new(lhs);
+            let mut right = ArrayConsumer::new(self);
+
+            let (left_array_iter, left_position) = left.iter_position();
+            let (right_array_iter, right_position) = right.iter_position();
+
+            FromIterator::from_iter(left_array_iter.zip(right_array_iter).map(|(l, r)| {
+                let left_value = ptr::read(l);
+                let right_value = ptr::read(r);
+
+                *left_position += 1;
+                *right_position += 1;
+
+                f(left_value, right_value)
+            }))
+        }
+    }
+
+    #[doc(hidden)]
+    fn inverted_zip2<B, Lhs, U, F>(self, lhs: Lhs, mut f: F) -> MappedSequence<Lhs, B, U>
+    where
+        Lhs: GenericSequence<B, Length = Self::Length> + MappedGenericSequence<B, U>,
+        Self: MappedGenericSequence<T, U>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        F: FnMut(Lhs::Item, Self::Item) -> U,
+    {
+        unsafe {
+            let mut right = ArrayConsumer::new(self);
+
+            let (right_array_iter, right_position) = right.iter_position();
+
+            FromIterator::from_iter(
+                lhs.into_iter()
+                    .zip(right_array_iter)
+                    .map(|(left_value, r)| {
+                        let right_value = ptr::read(r);
+
+                        *right_position += 1;
+
+                        f(left_value, right_value)
+                    }),
+            )
+        }
+    }
+}
+
+unsafe impl<T, U, N> MappedGenericSequence<T, U> for GenericArray<T, N>
+where
+    N: ArrayLength<T> + ArrayLength<U>,
+    GenericArray<U, N>: GenericSequence<U, Length = N>,
+{
+    type Mapped = GenericArray<U, N>;
+}
+
+unsafe impl<T, N> FunctionalSequence<T> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    Self: GenericSequence<T, Item = T, Length = N>,
+{
+    fn map<U, F>(self, mut f: F) -> MappedSequence<Self, T, U>
+    where
+        Self::Length: ArrayLength<U>,
+        Self: MappedGenericSequence<T, U>,
+        F: FnMut(T) -> U,
+    {
+        unsafe {
+            let mut source = ArrayConsumer::new(self);
+
+            let (array_iter, position) = source.iter_position();
+
+            FromIterator::from_iter(array_iter.map(|src| {
+                let value = ptr::read(src);
+
+                *position += 1;
+
+                f(value)
+            }))
+        }
+    }
+
+    #[inline]
+    fn zip<B, Rhs, U, F>(self, rhs: Rhs, f: F) -> MappedSequence<Self, T, U>
+    where
+        Self: MappedGenericSequence<T, U>,
+        Rhs: MappedGenericSequence<B, U, Mapped = MappedSequence<Self, T, U>>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        Rhs: GenericSequence<B, Length = Self::Length>,
+        F: FnMut(T, Rhs::Item) -> U,
+    {
+        rhs.inverted_zip(self, f)
+    }
+
+    fn fold<U, F>(self, init: U, mut f: F) -> U
+    where
+        F: FnMut(U, T) -> U,
+    {
+        unsafe {
+            let mut source = ArrayConsumer::new(self);
+
+            let (array_iter, position) = source.iter_position();
+
+            array_iter.fold(init, |acc, src| {
+                let value = ptr::read(src);
+
+                *position += 1;
+
+                f(acc, value)
+            })
+        }
+    }
+}
+
+impl<T, N> GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    /// Extracts a slice containing the entire array.
+    #[inline]
+    pub fn as_slice(&self) -> &[T] {
+        self.deref()
+    }
+
+    /// Extracts a mutable slice containing the entire array.
+    #[inline]
+    pub fn as_mut_slice(&mut self) -> &mut [T] {
+        self.deref_mut()
+    }
+
+    /// Converts slice to a generic array reference with inferred length;
+    ///
+    /// Length of the slice must be equal to the length of the array.
+    #[inline]
+    pub fn from_slice(slice: &[T]) -> &GenericArray<T, N> {
+        slice.into()
+    }
+
+    /// Converts mutable slice to a mutable generic array reference
+    ///
+    /// Length of the slice must be equal to the length of the array.
+    #[inline]
+    pub fn from_mut_slice(slice: &mut [T]) -> &mut GenericArray<T, N> {
+        slice.into()
+    }
+}
+
+impl<'a, T, N: ArrayLength<T>> From<&'a [T]> for &'a GenericArray<T, N> {
+    /// Converts slice to a generic array reference with inferred length;
+    ///
+    /// Length of the slice must be equal to the length of the array.
+    #[inline]
+    fn from(slice: &[T]) -> &GenericArray<T, N> {
+        assert_eq!(slice.len(), N::USIZE);
+
+        unsafe { &*(slice.as_ptr() as *const GenericArray<T, N>) }
+    }
+}
+
+impl<'a, T, N: ArrayLength<T>> From<&'a mut [T]> for &'a mut GenericArray<T, N> {
+    /// Converts mutable slice to a mutable generic array reference
+    ///
+    /// Length of the slice must be equal to the length of the array.
+    #[inline]
+    fn from(slice: &mut [T]) -> &mut GenericArray<T, N> {
+        assert_eq!(slice.len(), N::USIZE);
+
+        unsafe { &mut *(slice.as_mut_ptr() as *mut GenericArray<T, N>) }
+    }
+}
+
+impl<T: Clone, N> GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    /// Construct a `GenericArray` from a slice by cloning its content
+    ///
+    /// Length of the slice must be equal to the length of the array
+    #[inline]
+    pub fn clone_from_slice(list: &[T]) -> GenericArray<T, N> {
+        Self::from_exact_iter(list.iter().cloned())
+            .expect("Slice must be the same length as the array")
+    }
+}
+
+impl<T, N> GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+{
+    /// Creates a new `GenericArray` instance from an iterator with a specific size.
+    ///
+    /// Returns `None` if the size is not equal to the number of elements in the `GenericArray`.
+    pub fn from_exact_iter<I>(iter: I) -> Option<Self>
+    where
+        I: IntoIterator<Item = T>,
+    {
+        let mut iter = iter.into_iter();
+
+        unsafe {
+            let mut destination = ArrayBuilder::new();
+
+            {
+                let (destination_iter, position) = destination.iter_position();
+
+                destination_iter.zip(&mut iter).for_each(|(dst, src)| {
+                    ptr::write(dst, src);
+
+                    *position += 1;
+                });
+
+                // The iterator produced fewer than `N` elements.
+                if *position != N::USIZE {
+                    return None;
+                }
+
+                // The iterator produced more than `N` elements.
+                if iter.next().is_some() {
+                    return None;
+                }
+            }
+
+            Some(destination.into_inner())
+        }
+    }
+}
+
+/// A reimplementation of the `transmute` function, avoiding problems
+/// when the compiler can't prove equal sizes.
+#[inline]
+#[doc(hidden)]
+pub unsafe fn transmute<A, B>(a: A) -> B {
+    let a = ManuallyDrop::new(a);
+    ::core::ptr::read(&*a as *const A as *const B)
+}
+
+#[cfg(test)]
+mod test {
+    // Compile with:
+    // cargo rustc --lib --profile test --release --
+    //      -C target-cpu=native -C opt-level=3 --emit asm
+    // and view the assembly to make sure test_assembly generates
+    // SIMD instructions instead of a naive loop.
+
+    #[inline(never)]
+    pub fn black_box<T>(val: T) -> T {
+        use core::{mem, ptr};
+
+        let ret = unsafe { ptr::read_volatile(&val) };
+        mem::forget(val);
+        ret
+    }
+
+    #[test]
+    fn test_assembly() {
+        use crate::functional::*;
+
+        let a = black_box(arr![i32; 1, 3, 5, 7]);
+        let b = black_box(arr![i32; 2, 4, 6, 8]);
+
+        let c = (&a).zip(b, |l, r| l + r);
+
+        let d = a.fold(0, |a, x| a + x);
+
+        assert_eq!(c, arr![i32; 3, 7, 11, 15]);
+
+        assert_eq!(d, 16);
+    }
+}
diff --git a/third_party/rust/generic-array/src/sequence.rs b/third_party/rust/generic-array/src/sequence.rs
new file mode 100644
index 0000000000..0119d3db67
--- /dev/null
+++ b/third_party/rust/generic-array/src/sequence.rs
@@ -0,0 +1,380 @@
+//! Useful traits for manipulating sequences of data stored in `GenericArray`s
+
+use super::*;
+use core::ops::{Add, Sub};
+use core::mem::MaybeUninit;
+use core::ptr;
+use typenum::operator_aliases::*;
+
+/// Defines some sequence with an associated length and iteration capabilities.
+///
+/// This is useful for passing N-length generic arrays as generics.
+pub unsafe trait GenericSequence<T>: Sized + IntoIterator {
+    /// `GenericArray` associated length
+    type Length: ArrayLength<T>;
+
+    /// Concrete sequence type used in conjuction with reference implementations of `GenericSequence`
+    type Sequence: GenericSequence<T, Length = Self::Length> + FromIterator<T>;
+
+    /// Initializes a new sequence instance using the given function.
+    ///
+    /// If the generator function panics while initializing the sequence,
+    /// any already initialized elements will be dropped.
+    fn generate<F>(f: F) -> Self::Sequence
+    where
+        F: FnMut(usize) -> T;
+
+    #[doc(hidden)]
+    fn inverted_zip<B, U, F>(
+        self,
+        lhs: GenericArray<B, Self::Length>,
+        mut f: F,
+    ) -> MappedSequence<GenericArray<B, Self::Length>, B, U>
+    where
+        GenericArray<B, Self::Length>: GenericSequence<B, Length = Self::Length>
+            + MappedGenericSequence<B, U>,
+        Self: MappedGenericSequence<T, U>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        F: FnMut(B, Self::Item) -> U,
+    {
+        unsafe {
+            let mut left = ArrayConsumer::new(lhs);
+
+            let (left_array_iter, left_position) = left.iter_position();
+
+            FromIterator::from_iter(left_array_iter.zip(self.into_iter()).map(
+                |(l, right_value)| {
+                        let left_value = ptr::read(l);
+
+                        *left_position += 1;
+
+                        f(left_value, right_value)
+                },
+            ))
+        }
+    }
+
+    #[doc(hidden)]
+    fn inverted_zip2<B, Lhs, U, F>(self, lhs: Lhs, mut f: F) -> MappedSequence<Lhs, B, U>
+    where
+        Lhs: GenericSequence<B, Length = Self::Length> + MappedGenericSequence<B, U>,
+        Self: MappedGenericSequence<T, U>,
+        Self::Length: ArrayLength<B> + ArrayLength<U>,
+        F: FnMut(Lhs::Item, Self::Item) -> U,
+    {
+        FromIterator::from_iter(lhs.into_iter().zip(self.into_iter()).map(|(l, r)| f(l, r)))
+    }
+}
+
+/// Accessor for `GenericSequence` item type, which is really `IntoIterator::Item`
+///
+/// For deeply nested generic mapped sequence types, like shown in `tests/generics.rs`,
+/// this can be useful for keeping things organized.
+pub type SequenceItem<T> = <T as IntoIterator>::Item;
+
+unsafe impl<'a, T: 'a, S: GenericSequence<T>> GenericSequence<T> for &'a S
+where
+    &'a S: IntoIterator,
+{
+    type Length = S::Length;
+    type Sequence = S::Sequence;
+
+    #[inline]
+    fn generate<F>(f: F) -> Self::Sequence
+    where
+        F: FnMut(usize) -> T,
+    {
+        S::generate(f)
+    }
+}
+
+unsafe impl<'a, T: 'a, S: GenericSequence<T>> GenericSequence<T> for &'a mut S
+where
+    &'a mut S: IntoIterator,
+{
+    type Length = S::Length;
+    type Sequence = S::Sequence;
+
+    #[inline]
+    fn generate<F>(f: F) -> Self::Sequence
+    where
+        F: FnMut(usize) -> T,
+    {
+        S::generate(f)
+    }
+}
+
+/// Defines any `GenericSequence` which can be lengthened or extended by appending
+/// or prepending an element to it.
+///
+/// Any lengthened sequence can be shortened back to the original using `pop_front` or `pop_back`
+pub unsafe trait Lengthen<T>: Sized + GenericSequence<T> {
+    /// `GenericSequence` that has one more element than `Self`
+    type Longer: Shorten<T, Shorter = Self>;
+
+    /// Returns a new array with the given element appended to the end of it.
+    ///
+    /// Example:
+    ///
+    /// ```rust
+    /// # use generic_array::{arr, sequence::Lengthen};
+    /// # fn main() {
+    /// let a = arr![i32; 1, 2, 3];
+    ///
+    /// let b = a.append(4);
+    ///
+    /// assert_eq!(b, arr![i32; 1, 2, 3, 4]);
+    /// # }
+    /// ```
+    fn append(self, last: T) -> Self::Longer;
+
+    /// Returns a new array with the given element prepended to the front of it.
+    ///
+    /// Example:
+    ///
+    /// ```rust
+    /// # use generic_array::{arr, sequence::Lengthen};
+    /// # fn main() {
+    /// let a = arr![i32; 1, 2, 3];
+    ///
+    /// let b = a.prepend(4);
+    ///
+    /// assert_eq!(b, arr![i32; 4, 1, 2, 3]);
+    /// # }
+    /// ```
+    fn prepend(self, first: T) -> Self::Longer;
+}
+
+/// Defines a `GenericSequence` which can be shortened by removing the first or last element from it.
+///
+/// Additionally, any shortened sequence can be lengthened by
+/// appending or prepending an element to it.
+pub unsafe trait Shorten<T>: Sized + GenericSequence<T> {
+    /// `GenericSequence` that has one less element than `Self`
+    type Shorter: Lengthen<T, Longer = Self>;
+
+    /// Returns a new array without the last element, and the last element.
+    ///
+    /// Example:
+    ///
+    /// ```rust
+    /// # use generic_array::{arr, sequence::Shorten};
+    /// # fn main() {
+    /// let a = arr![i32; 1, 2, 3, 4];
+    ///
+    /// let (init, last) = a.pop_back();
+    ///
+    /// assert_eq!(init, arr![i32; 1, 2, 3]);
+    /// assert_eq!(last, 4);
+    /// # }
+    /// ```
+    fn pop_back(self) -> (Self::Shorter, T);
+
+    /// Returns a new array without the first element, and the first element.
+    /// Example:
+    ///
+    /// ```rust
+    /// # use generic_array::{arr, sequence::Shorten};
+    /// # fn main() {
+    /// let a = arr![i32; 1, 2, 3, 4];
+    ///
+    /// let (head, tail) = a.pop_front();
+    ///
+    /// assert_eq!(head, 1);
+    /// assert_eq!(tail, arr![i32; 2, 3, 4]);
+    /// # }
+    /// ```
+    fn pop_front(self) -> (T, Self::Shorter);
+}
+
+unsafe impl<T, N: ArrayLength<T>> Lengthen<T> for GenericArray<T, N>
+where
+    N: Add<B1>,
+    Add1<N>: ArrayLength<T>,
+    Add1<N>: Sub<B1, Output = N>,
+    Sub1<Add1<N>>: ArrayLength<T>,
+{
+    type Longer = GenericArray<T, Add1<N>>;
+
+    fn append(self, last: T) -> Self::Longer {
+        let mut longer: MaybeUninit<Self::Longer> = MaybeUninit::uninit();
+
+        // Note this is *mut Self, so add(1) increments by the whole array
+        let out_ptr = longer.as_mut_ptr() as *mut Self;
+
+        unsafe {
+            // write self first
+            ptr::write(out_ptr, self);
+            // increment past self, then write the last
+            ptr::write(out_ptr.add(1) as *mut T, last);
+
+            longer.assume_init()
+        }
+    }
+
+    fn prepend(self, first: T) -> Self::Longer {
+        let mut longer: MaybeUninit<Self::Longer> = MaybeUninit::uninit();
+
+        // Note this is *mut T, so add(1) increments by a single T
+        let out_ptr = longer.as_mut_ptr() as *mut T;
+
+        unsafe {
+            // write the first at the start
+            ptr::write(out_ptr, first);
+            // increment past the first, then write self
+            ptr::write(out_ptr.add(1) as *mut Self, self);
+
+            longer.assume_init()
+        }
+    }
+}
+
+unsafe impl<T, N: ArrayLength<T>> Shorten<T> for GenericArray<T, N>
+where
+    N: Sub<B1>,
+    Sub1<N>: ArrayLength<T>,
+    Sub1<N>: Add<B1, Output = N>,
+    Add1<Sub1<N>>: ArrayLength<T>,
+{
+    type Shorter = GenericArray<T, Sub1<N>>;
+
+    fn pop_back(self) -> (Self::Shorter, T) {
+        let whole = ManuallyDrop::new(self);
+
+        unsafe {
+            let init = ptr::read(whole.as_ptr() as _);
+            let last = ptr::read(whole.as_ptr().add(Sub1::<N>::USIZE) as _);
+
+            (init, last)
+        }
+    }
+
+    fn pop_front(self) -> (T, Self::Shorter) {
+        // ensure this doesn't get dropped
+        let whole = ManuallyDrop::new(self);
+
+        unsafe {
+            let head = ptr::read(whole.as_ptr() as _);
+            let tail = ptr::read(whole.as_ptr().offset(1) as _);
+
+            (head, tail)
+        }
+    }
+}
+
+/// Defines a `GenericSequence` that can be split into two parts at a given pivot index.
+pub unsafe trait Split<T, K>: GenericSequence<T>
+where
+    K: ArrayLength<T>,
+{
+    /// First part of the resulting split array
+    type First: GenericSequence<T>;
+    /// Second part of the resulting split array
+    type Second: GenericSequence<T>;
+
+    /// Splits an array at the given index, returning the separate parts of the array.
+    fn split(self) -> (Self::First, Self::Second);
+}
+
+unsafe impl<T, N, K> Split<T, K> for GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    K: ArrayLength<T>,
+    N: Sub<K>,
+    Diff<N, K>: ArrayLength<T>,
+{
+    type First = GenericArray<T, K>;
+    type Second = GenericArray<T, Diff<N, K>>;
+
+    fn split(self) -> (Self::First, Self::Second) {
+        unsafe {
+            // ensure this doesn't get dropped
+            let whole = ManuallyDrop::new(self);
+
+            let head = ptr::read(whole.as_ptr() as *const _);
+            let tail = ptr::read(whole.as_ptr().add(K::USIZE) as *const _);
+
+            (head, tail)
+        }
+    }
+}
+
+unsafe impl<'a, T, N, K> Split<T, K> for &'a GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    K: ArrayLength<T> + 'static,
+    N: Sub<K>,
+    Diff<N, K>: ArrayLength<T>,
+{
+    type First = &'a GenericArray<T, K>;
+    type Second = &'a GenericArray<T, Diff<N, K>>;
+
+    fn split(self) -> (Self::First, Self::Second) {
+        unsafe {
+            let ptr_to_first: *const T = self.as_ptr();
+            let head = &*(ptr_to_first as *const _);
+            let tail = &*(ptr_to_first.add(K::USIZE) as *const _);
+            (head, tail)
+        }
+    }
+}
+
+unsafe impl<'a, T, N, K> Split<T, K> for &'a mut GenericArray<T, N>
+where
+    N: ArrayLength<T>,
+    K: ArrayLength<T> + 'static,
+    N: Sub<K>,
+    Diff<N, K>: ArrayLength<T>,
+{
+    type First = &'a mut GenericArray<T, K>;
+    type Second = &'a mut GenericArray<T, Diff<N, K>>;
+
+    fn split(self) -> (Self::First, Self::Second) {
+        unsafe {
+            let ptr_to_first: *mut T = self.as_mut_ptr();
+            let head = &mut *(ptr_to_first as *mut _);
+            let tail = &mut *(ptr_to_first.add(K::USIZE) as *mut _);
+            (head, tail)
+        }
+    }
+}
+
+/// Defines `GenericSequence`s which can be joined together, forming a larger array.
+pub unsafe trait Concat<T, M>: GenericSequence<T>
+where
+    M: ArrayLength<T>,
+{
+    /// Sequence to be concatenated with `self`
+    type Rest: GenericSequence<T, Length = M>;
+
+    /// Resulting sequence formed by the concatenation.
+    type Output: GenericSequence<T>;
+
+    /// Concatenate, or join, two sequences.
+    fn concat(self, rest: Self::Rest) -> Self::Output;
+}
+
+unsafe impl<T, N, M> Concat<T, M> for GenericArray<T, N>
+where
+    N: ArrayLength<T> + Add<M>,
+    M: ArrayLength<T>,
+    Sum<N, M>: ArrayLength<T>,
+{
+    type Rest = GenericArray<T, M>;
+    type Output = GenericArray<T, Sum<N, M>>;
+
+    fn concat(self, rest: Self::Rest) -> Self::Output {
+        let mut output: MaybeUninit<Self::Output> = MaybeUninit::uninit();
+
+        let out_ptr = output.as_mut_ptr() as *mut Self;
+
+        unsafe {
+            // write all of self to the pointer
+            ptr::write(out_ptr, self);
+            // increment past self, then write the rest
+            ptr::write(out_ptr.add(1) as *mut _, rest);
+
+            output.assume_init()
+        }
+    }
+}
author	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 00:47:55 +0000
committer	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-04-19 00:47:55 +0000
commit	26a029d407be480d791972afb5975cf62c9360a6 (patch)
tree	f435a8308119effd964b339f76abb83a57c29483 /third_party/rust/generic-array
parent	Initial commit. (diff)
download	firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip