Merge pull request #122 from kpreid/tobytes

Add implementations of `num_traits::{FromBytes, ToBytes}`.

Author: VoidStarKat

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 - Added support for `arbitrary` crate. Fixes [#110]. By [@FL33TW00D].
+- New `num-traits` implementations: `FromBytes` and `ToBytes` for `f16` and `bf16`. By [@kpreid].
 
 ### Fixed
 - Suppressed unexpected_cfg lint warnings on newer versions of stable Rust.
@@ -364,6 +365,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 [@eiz]: https://github.com/eiz
 [@comath]: https://github.com/comath
 [@FL33TW00D]: https://github.com/FL33TW00D
+[@kpreid]: https://github.com/kpreid
 
 
 [Unreleased]: https://github.com/starkat99/half-rs/compare/v2.4.1...HEAD

README.md

@@ -38,8 +38,9 @@ See the [crate documentation](https://docs.rs/half/) for more details.
 - **`serde`** - Implement `Serialize` and `Deserialize` traits for `f16` and `bf16`. This adds a
   dependency on the [`serde`](https://crates.io/crates/serde) crate.
 
-- **`num-traits`** — Enable `ToPrimitive`, `FromPrimitive`, `Num`, `Float`, `FloatCore` and
-  `Bounded` trait implementations from the [`num-traits`](https://crates.io/crates/num-traits) crate.
+- **`num-traits`** — Enable `ToPrimitive`, `FromPrimitive`, `ToBytes`, `FromBytes`, `Num`, `Float`,
+  `FloatCore` and `Bounded` trait implementations from the
+  [`num-traits`](https://crates.io/crates/num-traits) crate.
 
 - **`bytemuck`** — Enable `Zeroable` and `Pod` trait implementations from the
   [`bytemuck`](https://crates.io/crates/bytemuck) crate.

src/bfloat.rs

@@ -1332,7 +1332,7 @@ mod test {
     #[allow(unused_imports)]
     use core::cmp::Ordering;
     #[cfg(feature = "num-traits")]
-    use num_traits::{AsPrimitive, FromPrimitive, ToPrimitive};
+    use num_traits::{AsPrimitive, FromBytes, FromPrimitive, ToBytes, ToPrimitive};
     use quickcheck_macros::quickcheck;
 
     #[cfg(feature = "num-traits")]
@@ -1367,6 +1367,16 @@ mod test {
         assert_eq!(<bf16 as FromPrimitive>::from_f64(2.0).unwrap(), two);
     }
 
+    #[cfg(feature = "num-traits")]
+    #[test]
+    fn to_and_from_bytes() {
+        let two = bf16::from_f32(2.0);
+        assert_eq!(<bf16 as ToBytes>::to_le_bytes(&two), [0, 64]);
+        assert_eq!(<bf16 as FromBytes>::from_le_bytes(&[0, 64]), two);
+        assert_eq!(<bf16 as ToBytes>::to_be_bytes(&two), [64, 0]);
+        assert_eq!(<bf16 as FromBytes>::from_be_bytes(&[64, 0]), two);
+    }
+
     #[test]
     fn test_bf16_consts_from_f32() {
         let one = bf16::from_f32(1.0);

src/binary16.rs

@@ -1349,7 +1349,7 @@ mod test {
     #[allow(unused_imports)]
     use core::cmp::Ordering;
     #[cfg(feature = "num-traits")]
-    use num_traits::{AsPrimitive, FromPrimitive, ToPrimitive};
+    use num_traits::{AsPrimitive, FromBytes, FromPrimitive, ToBytes, ToPrimitive};
     use quickcheck_macros::quickcheck;
 
     #[cfg(feature = "num-traits")]
@@ -1384,6 +1384,16 @@ mod test {
         assert_eq!(<f16 as FromPrimitive>::from_f64(2.0).unwrap(), two);
     }
 
+    #[cfg(feature = "num-traits")]
+    #[test]
+    fn to_and_from_bytes() {
+        let two = f16::from_f32(2.0);
+        assert_eq!(<f16 as ToBytes>::to_le_bytes(&two), [0, 64]);
+        assert_eq!(<f16 as FromBytes>::from_le_bytes(&[0, 64]), two);
+        assert_eq!(<f16 as ToBytes>::to_be_bytes(&two), [64, 0]);
+        assert_eq!(<f16 as FromBytes>::from_be_bytes(&[64, 0]), two);
+    }
+
     #[test]
     fn test_f16_consts() {
         // DIGITS

src/lib.rs

@@ -88,8 +88,8 @@
 //!   [`Deserialize`] traits for both [`f16`] and [`bf16`].
 //!
 //! - **`num-traits`** — Adds support for the [`num-traits`] crate by implementing [`ToPrimitive`],
-//!   [`FromPrimitive`], [`AsPrimitive`], [`Num`], [`Float`], [`FloatCore`], and [`Bounded`] traits
-//!   for both [`f16`] and [`bf16`].
+//!   [`FromPrimitive`], [`ToBytes`], [`FromBytes`], [`AsPrimitive`], [`Num`], [`Float`],
+//!   [`FloatCore`], and [`Bounded`] traits for both [`f16`] and [`bf16`].
 //!
 //! - **`bytemuck`** — Adds support for the [`bytemuck`] crate by implementing [`Zeroable`] and
 //!   [`Pod`] traits for both [`f16`] and [`bf16`].
@@ -155,6 +155,8 @@
     doc = "
 [`ToPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.ToPrimitive.html
 [`FromPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.FromPrimitive.html
+[`ToBytes`]: https://docs.rs/num-traits/*/num_traits/ops/bytes/trait.ToBytes.html
+[`FromBytes`]: https://docs.rs/num-traits/*/num_traits/ops/bytes/trait.FromBytes.html
 [`AsPrimitive`]: https://docs.rs/num-traits/*/num_traits/cast/trait.AsPrimitive.html
 [`Num`]: https://docs.rs/num-traits/*/num_traits/trait.Num.html
 [`Float`]: https://docs.rs/num-traits/*/num_traits/float/trait.Float.html

src/num_traits.rs

@@ -2,7 +2,8 @@ use crate::{bf16, f16};
 use core::cmp::Ordering;
 use core::{num::FpCategory, ops::Div};
 use num_traits::{
-    AsPrimitive, Bounded, FloatConst, FromPrimitive, Num, NumCast, One, ToPrimitive, Zero,
+    AsPrimitive, Bounded, FloatConst, FromBytes, FromPrimitive, Num, NumCast, One, ToBytes,
+    ToPrimitive, Zero,
 };
 
 impl ToPrimitive for f16 {
@@ -744,6 +745,38 @@ impl_as_primitive_f16_from!(usize, from_f32);
 impl_as_primitive_f16_from!(f32, from_f32);
 impl_as_primitive_f16_from!(f64, from_f64);
 
+impl ToBytes for f16 {
+    type Bytes = [u8; 2];
+
+    fn to_be_bytes(&self) -> Self::Bytes {
+        Self::to_be_bytes(*self)
+    }
+
+    fn to_le_bytes(&self) -> Self::Bytes {
+        Self::to_le_bytes(*self)
+    }
+
+    fn to_ne_bytes(&self) -> Self::Bytes {
+        Self::to_ne_bytes(*self)
+    }
+}
+
+impl FromBytes for f16 {
+    type Bytes = [u8; 2];
+
+    fn from_be_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_be_bytes(*bytes)
+    }
+
+    fn from_le_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_le_bytes(*bytes)
+    }
+
+    fn from_ne_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_ne_bytes(*bytes)
+    }
+}
+
 impl ToPrimitive for bf16 {
     #[inline]
     fn to_i64(&self) -> Option<i64> {
@@ -1483,3 +1516,35 @@ impl_as_primitive_bf16_from!(isize, from_f32);
 impl_as_primitive_bf16_from!(usize, from_f32);
 impl_as_primitive_bf16_from!(f32, from_f32);
 impl_as_primitive_bf16_from!(f64, from_f64);
+
+impl ToBytes for bf16 {
+    type Bytes = [u8; 2];
+
+    fn to_be_bytes(&self) -> Self::Bytes {
+        Self::to_be_bytes(*self)
+    }
+
+    fn to_le_bytes(&self) -> Self::Bytes {
+        Self::to_le_bytes(*self)
+    }
+
+    fn to_ne_bytes(&self) -> Self::Bytes {
+        Self::to_ne_bytes(*self)
+    }
+}
+
+impl FromBytes for bf16 {
+    type Bytes = [u8; 2];
+
+    fn from_be_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_be_bytes(*bytes)
+    }
+
+    fn from_le_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_le_bytes(*bytes)
+    }
+
+    fn from_ne_bytes(bytes: &Self::Bytes) -> Self {
+        Self::from_ne_bytes(*bytes)
+    }
+}