Adding upstream version 86.0.1.upstream/86.0.1upstream

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

10 files changed, 1083 insertions, 0 deletions

diff --git a/third_party/rust/cast/.cargo-checksum.json b/third_party/rust/cast/.cargo-checksum.json
new file mode 100644
index 0000000000..dc2baf66d6
--- /dev/null
+++ b/third_party/rust/cast/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{"CHANGELOG.md":"b24b688b552ea12f4ef03b2c76e17ecfb8c05104d4f494c47b698fd7d94d3e3a","Cargo.toml":"3908d7c2421a4071d3fdd4a7c7a44c1c8779cf9d229cec307fd1a2b96398aa60","LICENSE-APACHE":"a60eea817514531668d7e00765731449fe14d059d3249e0bc93b36de45f759f2","LICENSE-MIT":"005b3f9b4687364514bbaea2a25e96d54ce6a59277d157386e8259cbcae8e095","README.md":"006ae145ee89fa14a9d755b206ec2011a3687408e9d5fe3943f2448767b01d62","ci/install.sh":"f3965bda34345579d0799ca2e581efd7ae51f3191aa9203b018f4ade8b986b15","ci/script.sh":"0f8329c7345731c12f35a392e8deeb2e265b75f107c5aca6eed584096896737f","src/lib.rs":"52418274bc4ec5c59dba1885de7324157e677739a2c9624b5d462d5d4c77b5e3","src/test.rs":"58ea38d755d5eae72b1df29fc602483fef888a111bb2e9c3a219e2b2a1ed222f"},"package":"926013f2860c46252efceabb19f4a6b308197505082c609025aa6706c011d427"}
\ No newline at end of file
diff --git a/third_party/rust/cast/CHANGELOG.md b/third_party/rust/cast/CHANGELOG.md
new file mode 100644
index 0000000000..d0019641b1
--- /dev/null
+++ b/third_party/rust/cast/CHANGELOG.md
@@ -0,0 +1,42 @@
+# Change Log
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+## [Unreleased]
+
+## [v0.2.2] - 2017-05-07
+
+### Fixed
+
+- UB in the checked cast from `f32` to `u128`.
+
+## [v0.2.1] - 2017-05-06
+
+### Added
+
+- Support for 128-bit integers, behind the `x128` Cargo feature (nightly
+  needed).
+
+## [v0.2.0] - 2017-02-08
+
+### Added
+
+- Now `cast::Error` implements the `std::error::Error` trait among other traits
+  like `Display`, `Clone`, etc.
+
+### Changed
+
+- [breaking-change] This crate now depends on the `std` crate by default but you
+  can make it `no_std` by opting out of the `std` Cargo feature.
+
+## v0.1.0 - 2016-02-07
+
+Initial release
+
+[Unreleased]: https://github.com/japaric/cast.rs/compare/v0.2.2...HEAD
+[v0.2.2]: https://github.com/japaric/cast.rs/compare/v0.2.1...v0.2.2
+[v0.2.1]: https://github.com/japaric/cast.rs/compare/v0.2.0...v0.2.1
+[v0.2.0]: https://github.com/japaric/cast.rs/compare/v0.1.0...v0.2.0
diff --git a/third_party/rust/cast/Cargo.toml b/third_party/rust/cast/Cargo.toml
new file mode 100644
index 0000000000..3534ad53a5
--- /dev/null
+++ b/third_party/rust/cast/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+description = "Ergonomic, checked cast functions for primitive types"
+documentation = "https://docs.rs/cast"
+keywords = ["checked", "cast", "primitive", "integer", "float"]
+license = "MIT OR Apache-2.0"
+name = "cast"
+repository = "https://github.com/japaric/cast.rs"
+version = "0.2.2"
+
+[features]
+# Assume we should use `std` unless asked to do otherwise.
+default = ["std"]
+# Enable this to get a std::error::Error impl for convenient use with other
+# libraries.
+std = []
+# Enable this for i128/u128 support
+x128 = []
+
+[dev-dependencies]
+quickcheck = "0.4.1"
diff --git a/third_party/rust/cast/LICENSE-APACHE b/third_party/rust/cast/LICENSE-APACHE
new file mode 100644
index 0000000000..16fe87b06e
--- /dev/null
+++ b/third_party/rust/cast/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
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+6. Trademarks. This License does not grant permission to use the trade
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+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
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+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
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+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
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+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
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+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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diff --git a/third_party/rust/cast/LICENSE-MIT b/third_party/rust/cast/LICENSE-MIT
new file mode 100644
index 0000000000..3c1a4ea664
--- /dev/null
+++ b/third_party/rust/cast/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2014-2017 Jorge Aparicio
+
+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.
diff --git a/third_party/rust/cast/README.md b/third_party/rust/cast/README.md
new file mode 100644
index 0000000000..3ed32f1979
--- /dev/null
+++ b/third_party/rust/cast/README.md
@@ -0,0 +1,44 @@
+[![crates.io](https://img.shields.io/crates/d/cast.svg)](https://crates.io/crates/cast)
+[![crates.io](https://img.shields.io/crates/v/cast.svg)](https://crates.io/crates/cast)
+
+# `cast`
+
+> Ergonomic, checked cast functions for primitive types
+
+``` rust
+extern crate cast;
+
+// `u8` and `u16` are checked cast functions, use them to cast from any numeric
+// primitive to `u8`/`u16` respectively
+use cast::{u8, u16, Error};
+
+// Infallible operations, like integer promotion, are equivalent to a normal
+// cast with `as`
+assert_eq!(u16(0u8), 0u16);
+
+// Everything else will return a `Result` depending on the success of the
+// operation
+assert_eq!(u8(0u16), Ok(0u8));
+assert_eq!(u8(256u16), Err(Error::Overflow));
+assert_eq!(u8(-1i8), Err(Error::Underflow));
+assert_eq!(u8(1. / 0.), Err(Error::Infinite));
+assert_eq!(u8(0. / 0.), Err(Error::NaN));
+```
+
+## [API docs](https://docs.rs/cast)
+
+## License
+
+Licensed under either of
+
+- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
+  http://www.apache.org/licenses/LICENSE-2.0)
+- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally submitted
+for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
+dual licensed as above, without any additional terms or conditions.
diff --git a/third_party/rust/cast/ci/install.sh b/third_party/rust/cast/ci/install.sh
new file mode 100644
index 0000000000..9ce7632486
--- /dev/null
+++ b/third_party/rust/cast/ci/install.sh
@@ -0,0 +1,21 @@
+set -ex
+
+main() {
+    curl https://sh.rustup.rs -sSf | \
+        sh -s -- -y --default-toolchain $TRAVIS_RUST_VERSION
+
+    local latest=$(git ls-remote --tags --refs --exit-code https://github.com/japaric/cross \
+                       | cut -d/ -f3 \
+                       | grep -E '^v[0-9.]+$' \
+                       | sort --version-sort \
+                       | tail -n1)
+
+    curl -LSfs https://japaric.github.io/trust/install.sh | \
+        sh -s -- \
+           --force \
+           --git japaric/cross \
+           --tag $latest \
+           --target x86_64-unknown-linux-gnu
+}
+
+main
diff --git a/third_party/rust/cast/ci/script.sh b/third_party/rust/cast/ci/script.sh
new file mode 100644
index 0000000000..4715638328
--- /dev/null
+++ b/third_party/rust/cast/ci/script.sh
@@ -0,0 +1,14 @@
+set -ex
+
+main() {
+    cross test --target $TARGET
+    cross test --target $TARGET --release
+
+    [ "$TRAVIS_RUST_VERSION" -eq "nightly" ] && cross test --feature x128 --target $TARGET
+    [ "$TRAVIS_RUST_VERSION" -eq "nightly" ] && cross test --feature x128 --target $TARGET --release
+
+    cross test --no-default-features --target $TARGET
+    cross test --no-default-features --target $TARGET --release
+}
+
+main
diff --git a/third_party/rust/cast/src/lib.rs b/third_party/rust/cast/src/lib.rs
new file mode 100644
index 0000000000..bccb921385
--- /dev/null
+++ b/third_party/rust/cast/src/lib.rs
@@ -0,0 +1,523 @@
+//! Ergonomic, checked cast functions for primitive types
+//!
+//! This crate provides one checked cast function for each numeric primitive.
+//! Use these functions to perform a cast from any other numeric primitive:
+//!
+//! ```
+//! extern crate cast;
+//!
+//! use cast::{u8, u16, Error};
+//!
+//! # fn main() {
+//! // Infallible operations, like integer promotion, are equivalent to a normal
+//! // cast with `as`
+//! assert_eq!(u16(0u8), 0u16);
+//!
+//! // Everything else will return a `Result` depending on the success of the
+//! // operation
+//! assert_eq!(u8(0u16), Ok(0u8));
+//! assert_eq!(u8(256u16), Err(Error::Overflow));
+//! assert_eq!(u8(-1i8), Err(Error::Underflow));
+//! assert_eq!(u8(1. / 0.), Err(Error::Infinite));
+//! assert_eq!(u8(0. / 0.), Err(Error::NaN));
+//! # }
+//! ```
+//!
+//! There are no namespace problems between these functions, the "primitive
+//! modules" in `core`/`std` and the built-in primitive types, so all them can
+//! be in the same scope:
+//!
+//! ```
+//! extern crate cast;
+//!
+//! use std::u8;
+//! use cast::{u8, u16};
+//!
+//! # fn main() {
+//! // `u8` as a type
+//! let x: u8 = 0;
+//! // `u8` as a module
+//! let y = u16(u8::MAX);
+//! // `u8` as a function
+//! let z = u8(y).unwrap();
+//! # }
+//! ```
+//!
+//! The checked cast functionality is also usable with type aliases via the
+//! `cast` static method:
+//!
+//! ```
+//! extern crate cast;
+//!
+//! use std::os::raw::c_ulonglong;
+//! // NOTE avoid shadowing `std::convert::From` - cf. rust-lang/rfcs#1311
+//! use cast::From as _0;
+//!
+//! # fn main() {
+//! assert_eq!(c_ulonglong::cast(0u8), 0u64);
+//! # }
+//! ```
+//!
+//! This crate also provides a `From` trait that can be used, for example,
+//! to create a generic function that accepts any type that can be infallibly
+//! casted to `u32`.
+//!
+//! ```
+//! extern crate cast;
+//!
+//! fn to_u32<T>(x: T) -> u32
+//!     // reads as: "where u32 can be casted from T with output u32"
+//!     where u32: cast::From<T, Output=u32>,
+//! {
+//!     cast::u32(x)
+//! }
+//!
+//! # fn main() {
+//! assert_eq!(to_u32(0u8), 0u32);
+//! assert_eq!(to_u32(1u16), 1u32);
+//! assert_eq!(to_u32(2u32), 2u32);
+//!
+//! // to_u32(-1i32);  // Compile error
+//! # }
+//! ```
+//!
+//! ## Building without `std`
+//!
+//! This crate can be used without Rust's `std` crate by declaring it as
+//! follows in your `Cargo.toml`:
+//!
+//! ``` toml
+//! cast = { version = "*", default-features = false }
+//! ```
+
+#![deny(missing_docs)]
+#![deny(warnings)]
+#![allow(const_err)]
+
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#![cfg_attr(feature = "x128", feature(i128_type, i128))]
+
+#[cfg(feature = "std")]
+extern crate core;
+
+#[cfg(test)]
+#[macro_use]
+extern crate quickcheck;
+
+use core::fmt;
+#[cfg(feature="std")]
+use std::error;
+
+#[cfg(test)]
+mod test;
+
+/// Cast errors
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum Error {
+    /// Infinite value casted to a type that can only represent finite values
+    Infinite,
+    /// NaN value casted to a type that can't represent a NaN value
+    NaN,
+    /// Source value is greater than the maximum value that the destination type
+    /// can hold
+    Overflow,
+    /// Source value is smaller than the minimum value that the destination type
+    /// can hold
+    Underflow,
+}
+
+impl Error {
+    /// A private helper function that implements `description`, because
+    /// `description` is only available when we have `std` enabled.
+    fn description_helper(&self) -> &str {
+        match *self {
+            Error::Infinite => "Cannot store infinite value in finite type",
+            Error::NaN => "Cannot store NaN in type which does not support it",
+            Error::Overflow => "Overflow during numeric conversion",
+            Error::Underflow => "Underflow during numeric conversion",
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.description_helper())
+    }
+}
+
+#[cfg(feature="std")]
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        self.description_helper()
+    }
+}
+
+/// The "cast from" operation
+pub trait From<Src> {
+    /// The result of the cast operation: either `Self` or `Result<Self, Error>`
+    type Output;
+
+    /// Checked cast from `Src` to `Self`
+    fn cast(Src) -> Self::Output;
+}
+
+macro_rules! fns {
+    ($($ty:ident),+) => {
+        $(
+            /// Checked cast function
+            #[inline]
+            pub fn $ty<T>(x: T) -> <$ty as From<T>>::Output
+                where $ty: From<T>
+            {
+                <$ty as From<T>>::cast(x)
+            }
+         )+
+    }
+}
+
+fns!(f32, f64, i8, i16, i32, i64, isize, u8, u16, u32, u64, usize);
+
+#[cfg(feature = "x128")]
+fns!(i128, u128);
+
+/// `$dst` can hold any value of `$src`
+macro_rules! promotion {
+    ($($src:ty => $($dst: ty),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = $dst;
+
+                    #[inline]
+                    fn cast(src: $src) -> $dst {
+                        src as $dst
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// `$dst` can hold any positive value of `$src`
+macro_rules! half_promotion {
+    ($($src:ty => $($dst:ty),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        if src < 0 {
+                            Err(Error::Underflow)
+                        } else {
+                            Ok(src as $dst)
+                        }
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From an unsigned `$src` to a smaller `$dst`
+macro_rules! from_unsigned {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::$dst;
+
+                        if src > $dst::MAX as $src {
+                            Err(Error::Overflow)
+                        } else {
+                            Ok(src as $dst)
+                        }
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a signed `$src` to a smaller `$dst`
+macro_rules! from_signed {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::$dst;
+
+                        Err(if src < $dst::MIN as $src {
+                            Error::Underflow
+                        } else if src > $dst::MAX as $src {
+                            Error::Overflow
+                        } else {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a float `$src` to an integer `$dst`
+macro_rules! from_float {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::{$dst, $src};
+
+                        Err(if src != src {
+                            Error::NaN
+                        } else if src == $src::INFINITY ||
+                            src == $src::NEG_INFINITY {
+                            Error::Infinite
+                        } else if src < $dst::MIN as $src {
+                            Error::Underflow
+                        } else if src > $dst::MAX as $src {
+                            Error::Overflow
+                        } else {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+/// From a float `$src` to an integer `$dst`, where $dst is large enough to contain
+/// all values of `$src`. We can't ever overflow here
+macro_rules! from_float_dst {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            $(
+                impl From<$src> for $dst {
+                    type Output = Result<$dst, Error>;
+
+                    #[inline]
+                    #[allow(unused_comparisons)]
+                    fn cast(src: $src) -> Self::Output {
+                        use core::{$dst, $src};
+
+                        Err(if src != src {
+                            Error::NaN
+                        } else if src == $src::INFINITY ||
+                            src == $src::NEG_INFINITY {
+                            Error::Infinite
+                        } else if ($dst::MIN == 0) && src < 0.0 {
+                            Error::Underflow
+                        } else {
+                            return Ok(src as $dst);
+                        })
+                    }
+                }
+            )+
+        )+
+    }
+}
+
+// PLAY TETRIS! ;-)
+
+#[cfg(target_pointer_width = "32")]
+mod _32 {
+    use {Error, From};
+
+    // Signed
+    promotion! {
+        i8    => f32, f64, i8, i16, i32, isize, i64;
+        i16   => f32, f64,     i16, i32, isize, i64;
+        i32   => f32, f64,          i32, isize, i64;
+        isize => f32, f64,          i32, isize, i64;
+        i64   => f32, f64,                      i64;
+    }
+
+    half_promotion! {
+        i8    =>                                     u8, u16, u32, usize, u64;
+        i16   =>                                         u16, u32, usize, u64;
+        i32   =>                                              u32, usize, u64;
+        isize =>                                              u32, usize, u64;
+        i64   =>                                                          u64;
+    }
+
+    from_signed! {
+
+        i16   =>           i8,                       u8;
+        i32   =>           i8, i16,                  u8, u16;
+        isize =>           i8, i16,                  u8, u16;
+        i64   =>           i8, i16, i32, isize,      u8, u16, u32, usize;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    => f32, f64,     i16, i32, isize, i64, u8, u16, u32, usize, u64;
+        u16   => f32, f64,          i32, isize, i64,     u16, u32, usize, u64;
+        u32   => f32, f64,                      i64,          u32, usize, u64;
+        usize => f32, f64,                      i64,          u32, usize, u64;
+        u64   => f32, f64,                                                u64;
+    }
+
+    from_unsigned! {
+        u8    =>           i8;
+        u16   =>           i8, i16,                  u8;
+        u32   =>           i8, i16, i32, isize,      u8, u16;
+        usize =>           i8, i16, i32, isize,      u8, u16;
+        u64   =>           i8, i16, i32, isize, i64, u8, u16, u32, usize;
+    }
+
+    // Float
+    promotion! {
+        f32   => f32, f64;
+        f64   =>      f64;
+    }
+
+    from_float! {
+        f32   =>           i8, i16, i32, isize, i64, u8, u16, u32, usize, u64;
+        f64   =>           i8, i16, i32, isize, i64, u8, u16, u32, usize, u64;
+    }
+}
+
+#[cfg(target_pointer_width = "64")]
+mod _64 {
+    use {Error, From};
+
+    // Signed
+    promotion! {
+        i8    => f32, f64, i8, i16, i32, i64, isize;
+        i16   => f32, f64,     i16, i32, i64, isize;
+        i32   => f32, f64,          i32, i64, isize;
+        i64   => f32, f64,               i64, isize;
+        isize => f32, f64,               i64, isize;
+    }
+
+    half_promotion! {
+        i8    =>                                     u8, u16, u32, u64, usize;
+        i16   =>                                         u16, u32, u64, usize;
+        i32   =>                                              u32, u64, usize;
+        i64   =>                                                   u64, usize;
+        isize =>                                                   u64, usize;
+    }
+
+    from_signed! {
+
+        i16   =>           i8,                       u8;
+        i32   =>           i8, i16,                  u8, u16;
+        i64   =>           i8, i16, i32,             u8, u16, u32;
+        isize =>           i8, i16, i32,             u8, u16, u32;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    => f32, f64,     i16, i32, i64, isize, u8, u16, u32, u64, usize;
+        u16   => f32, f64,          i32, i64, isize,     u16, u32, u64, usize;
+        u32   => f32, f64,               i64, isize,          u32, u64, usize;
+        u64   => f32, f64,                                         u64, usize;
+        usize => f32, f64,                                         u64, usize;
+    }
+
+    from_unsigned! {
+        u8    =>           i8;
+        u16   =>           i8, i16,                  u8;
+        u32   =>           i8, i16, i32,             u8, u16;
+        u64   =>           i8, i16, i32, i64, isize, u8, u16, u32;
+        usize =>           i8, i16, i32, i64, isize, u8, u16, u32;
+    }
+
+    // Float
+    promotion! {
+        f32  => f32, f64;
+        f64  =>      f64;
+    }
+
+    from_float! {
+        f32  =>           i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+        f64  =>           i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+    }
+}
+
+#[cfg(feature = "x128")]
+mod _x128 {
+    use {Error, From};
+
+    // Signed
+    promotion! {
+        i8    =>                              i128;
+        i16   =>                              i128;
+        i32   =>                              i128;
+        i64   =>                              i128;
+        isize =>                              i128;
+        i128  => f32, f64,                    i128;
+    }
+
+    half_promotion! {
+        i8    =>                                                              u128;
+        i16   =>                                                              u128;
+        i32   =>                                                              u128;
+        i64   =>                                                              u128;
+        isize =>                                                              u128;
+        i128  =>                                                              u128;
+    }
+
+    from_signed! {
+        i128  =>           i8, i16, i32, i64,       isize, u8, u16, u32, u64,       usize;
+    }
+
+    // Unsigned
+    promotion! {
+        u8    =>                              i128,                           u128;
+        u16   =>                              i128,                           u128;
+        u32   =>                              i128,                           u128;
+        u64   =>                              i128,                           u128;
+        usize =>                              i128,                           u128;
+        u128  =>      f64,                                                    u128;
+    }
+
+    from_unsigned! {
+        u128 => f32,       i8, i16, i32, i64, i128, isize, u8, u16, u32, u64,       usize;
+    }
+
+    // Float
+    from_float! {
+        f32  => i128;
+        f64  => i128, u128;
+    }
+    from_float_dst! {
+        f32  => u128;
+    }
+}
+
+// The missing piece
+impl From<f64> for f32 {
+    type Output = Result<f32, Error>;
+
+    #[inline]
+    fn cast(src: f64) -> Self::Output {
+        use core::{f32, f64};
+
+        if src != src || src == f64::INFINITY || src == f64::NEG_INFINITY {
+            Ok(src as f32)
+        } else if src < f32::MIN as f64 {
+            Err(Error::Underflow)
+        } else if src > f32::MAX as f64 {
+            Err(Error::Overflow)
+        } else {
+            Ok(src as f32)
+        }
+    }
+}
diff --git a/third_party/rust/cast/src/test.rs b/third_party/rust/cast/src/test.rs
new file mode 100644
index 0000000000..8e34f9c4bc
--- /dev/null
+++ b/third_party/rust/cast/src/test.rs
@@ -0,0 +1,191 @@
+// If `src` can be promoted to `$dst`, then it must be Ok to cast `dst` back to
+// `$src`
+macro_rules! promote_and_back {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        mod demoting_to {
+            $(
+                mod $src {
+                    mod from {
+                        use From;
+
+                        $(
+                            quickcheck! {
+                                fn $dst(src: $src) -> bool {
+                                    $src::cast($dst::cast(src)).is_ok()
+                                }
+                            }
+                         )+
+                    }
+                }
+             )+
+        }
+    }
+}
+
+#[cfg(target_pointer_width = "32")]
+promote_and_back! {
+    i8    => f32, f64,     i16, i32, isize, i64                          ;
+    i16   => f32, f64,          i32, isize, i64                          ;
+    i32   => f32, f64,                      i64                          ;
+    isize => f32, f64,                      i64                          ;
+    i64   => f32, f64                                                    ;
+    u8    => f32, f64,     i16, i32, isize, i64,     u16, u32, usize, u64;
+    u16   => f32, f64,          i32, isize, i64,          u32, usize, u64;
+    u32   => f32, f64,                      i64,                      u64;
+    usize => f32, f64,                      i64,                      u64;
+    u64   => f32, f64                                                    ;
+}
+
+#[cfg(target_pointer_width = "64")]
+promote_and_back! {
+    i8    => f32, f64,     i16, i32, i64, isize                          ;
+    i16   => f32, f64,          i32, i64, isize                          ;
+    i32   => f32, f64,               i64, isize                          ;
+    i64   => f32, f64                                                    ;
+    isize => f32, f64                                                    ;
+    u8    => f32, f64,     i16, i32, i64, isize,     u16, u32, u64, usize;
+    u16   => f32, f64,          i32, i64, isize,          u32, u64, usize;
+    u32   => f32, f64,               i64, isize,               u64, usize;
+    u64   => f32, f64                                                    ;
+    usize => f32, f64                                                    ;
+}
+
+// TODO uncomment this once quickcheck supports Arbitrary for i128/u128
+// https://github.com/BurntSushi/quickcheck/issues/162
+/*#[cfg(feature = "x128")]
+promote_and_back! {
+    i8    =>           i128      ;
+    i16   =>           i128      ;
+    i32   =>           i128      ;
+    isize =>           i128      ;
+    i64   =>           i128      ;
+    i128  => f32, f64            ;
+    u8    =>           i128, u128;
+    u16   =>           i128, u128;
+    u32   =>           i128, u128;
+    usize =>           i128, u128;
+    u64   =>           i128, u128;
+    u128  => f32, f64            ;
+}*/
+
+// If it's Ok to cast `src` to `$dst`, it must also be Ok to cast `dst` back to
+// `$src`
+macro_rules! symmetric_cast_between {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        mod symmetric_cast_between {
+            $(
+                mod $src {
+                    mod and {
+                        use quickcheck::TestResult;
+
+                        use From;
+
+                        $(
+                            quickcheck! {
+                                fn $dst(src: $src) -> TestResult {
+                                    if let Ok(dst) = $dst::cast(src) {
+                                        TestResult::from_bool(
+                                            $src::cast(dst).is_ok())
+                                    } else {
+                                        TestResult::discard()
+                                    }
+                                }
+                            }
+                         )+
+                    }
+                }
+             )+
+        }
+    }
+}
+
+#[cfg(target_pointer_width = "32")]
+symmetric_cast_between! {
+    u8    =>           i8                      ;
+    u16   =>           i8, i16                 ;
+    u32   =>           i8, i16, i32            ;
+    usize =>           i8, i16, i32            ;
+    u64   =>           i8, i16, i32, i64, isize;
+}
+
+#[cfg(target_pointer_width = "64")]
+symmetric_cast_between! {
+    u8    =>           i8                      ;
+    u16   =>           i8, i16                 ;
+    u32   =>           i8, i16, i32            ;
+    u64   =>           i8, i16, i32, i64, isize;
+    usize =>           i8, i16, i32, i64, isize;
+}
+
+// TODO uncomment this once quickcheck supports Arbitrary for i128/u128
+// https://github.com/BurntSushi/quickcheck/issues/162
+/*#[cfg(feature = "x128")]
+symmetric_cast_between! {
+    u128  => i8, i16, i32, isize, i64, i128;
+}*/
+
+macro_rules! from_float {
+    ($($src:ident => $($dst:ident),+);+;) => {
+        $(
+            mod $src {
+                mod inf {
+                    mod to {
+                        use {Error, From};
+
+                        $(
+                            #[test]
+                            fn $dst() {
+                                let _0: $src = 0.;
+                                let _1: $src = 1.;
+                                let inf = _1 / _0;
+                                let neg_inf = -_1 / _0;
+
+                                assert_eq!($dst::cast(inf),
+                                           Err(Error::Infinite));
+                                assert_eq!($dst::cast(neg_inf),
+                                           Err(Error::Infinite));
+                            }
+                         )+
+                    }
+                }
+
+                mod nan {
+                    mod to {
+                        use {Error, From};
+
+                        $(
+                            #[test]
+                            fn $dst() {
+                                let _0: $src = 0.;
+                                let nan = _0 / _0;
+
+                                assert_eq!($dst::cast(nan),
+                                           Err(Error::NaN));
+                            }
+                         )+
+                    }
+                }
+            }
+         )+
+    }
+}
+
+from_float! {
+    f32 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+    f64 => i8, i16, i32, i64, isize, u8, u16, u32, u64, usize;
+}
+
+// TODO uncomment this once quickcheck supports Arbitrary for i128/u128
+// https://github.com/BurntSushi/quickcheck/issues/162
+/*#[cfg(feature = "x128")]
+from_float! {
+    f32 => i128, u128;
+    f64 => i128, u128;
+}*/
+
+#[test]
+#[cfg(feature = "x128")]
+fn test_fl_conversion() {
+    use u128;
+    assert_eq!(u128(42.0f32), Ok(42));
+}