num-traits/RELEASES.md

# Release 0.2.5

- [Documentation for `mul_add` now clarifies that it's not always faster.][70]
- [The default methods in `FromPrimitive` and `ToPrimitive` are more robust.][73]

**Contributors**: @cuviper, @frewsxcv

[70]: https://github.com/rust-num/num-traits/pull/70
[73]: https://github.com/rust-num/num-traits/pull/73

# Release 0.2.4

- [Support for 128-bit integers is now automatically detected and enabled.][69]
  Setting the `i128` crate feature now causes the build script to panic if such
  support is not detected.

**Contributors**: @cuviper

[69]: https://github.com/rust-num/num-traits/pull/69

# Release 0.2.3

- [The new `CheckedNeg` and `CheckedRem` traits][63] perform checked `Neg` and
  `Rem`, returning `Some(output)` or `None` on overflow.
- [The `no_std` implementation of `FloatCore::to_degrees` for `f32`][61] now
  uses a constant for greater accuracy, mirroring [rust#47919].  (With `std` it
  just calls the inherent `f32::to_degrees` in the standard library.)
- [The new `MulAdd` and `MulAddAssign` traits][59] perform a fused multiply-
  add.  For integer types this is just a convenience, but for floating point
  types this produces a more accurate result than the separate operations.
- [All applicable traits are now implemented for 128-bit integers][60] starting
  with Rust 1.26, enabled by the new `i128` crate feature.  The `FromPrimitive`
  and `ToPrimitive` traits now also have corresponding 128-bit methods, which
  default to converting via 64-bit integers for compatibility.

**Contributors**: @cuviper, @LEXUGE, @regexident, @vks

[59]: https://github.com/rust-num/num-traits/pull/59
[60]: https://github.com/rust-num/num-traits/pull/60
[61]: https://github.com/rust-num/num-traits/pull/61
[63]: https://github.com/rust-num/num-traits/pull/63
[rust#47919]: https://github.com/rust-lang/rust/pull/47919

# Release 0.2.2

- [Casting from floating point to integers now returns `None` on overflow][52],
  avoiding [rustc's undefined behavior][rust-10184]. This applies to the `cast`
  function and the traits `NumCast`, `FromPrimitive`, and `ToPrimitive`.

**Contributors**: @apopiak, @cuviper, @dbarella

[52]: https://github.com/rust-num/num-traits/pull/52
[rust-10184]: https://github.com/rust-lang/rust/issues/10184


# Release 0.2.1

- [The new `FloatCore` trait][32] offers a subset of `Float` for `#![no_std]` use.
  [This includes everything][41] except the transcendental functions and FMA.
- [The new `Inv` trait][37] returns the multiplicative inverse, or reciprocal.
- [The new `Pow` trait][37] performs exponentiation, much like the existing `pow`
  function, but with generic exponent types.
- [The new `One::is_one` method][39] tests if a value equals 1.  Implementers
  should override this method if there's a more efficient way to check for 1,
  rather than comparing with a temporary `one()`.

**Contributors**: @clarcharr, @cuviper, @vks

[32]: https://github.com/rust-num/num-traits/pull/32
[37]: https://github.com/rust-num/num-traits/pull/37
[39]: https://github.com/rust-num/num-traits/pull/39
[41]: https://github.com/rust-num/num-traits/pull/41


# Release 0.2.0

- **breaking change**: [There is now a `std` feature][30], enabled by default, along
  with the implication that building *without* this feature makes this a
  `#![no_std]` crate.
  - The `Float` and `Real` traits are only available when `std` is enabled.
  - Otherwise, the API is unchanged, and num-traits 0.1.43 now re-exports its
    items from num-traits 0.2 for compatibility (the [semver-trick]).

**Contributors**: @cuviper, @termoshtt, @vks

[semver-trick]: https://github.com/dtolnay/semver-trick
[30]: https://github.com/rust-num/num-traits/pull/30


# Release 0.1.43

- All items are now [re-exported from num-traits 0.2][31] for compatibility.

[31]: https://github.com/rust-num/num-traits/pull/31


# Release 0.1.42

- [num-traits now has its own source repository][num-356] at [rust-num/num-traits][home].
- [`ParseFloatError` now implements `Display`][22].
- [The new `AsPrimitive` trait][17] implements generic casting with the `as` operator.
- [The new `CheckedShl` and `CheckedShr` traits][21] implement generic
  support for the `checked_shl` and `checked_shr` methods on primitive integers.
- [The new `Real` trait][23] offers a subset of `Float` functionality that may be applicable to more
  types, with a blanket implementation for all existing `T: Float` types.

Thanks to @cuviper, @Enet4, @fabianschuiki, @svartalf, and @yoanlcq for their contributions!

[home]: https://github.com/rust-num/num-traits
[num-356]: https://github.com/rust-num/num/pull/356
[17]: https://github.com/rust-num/num-traits/pull/17
[21]: https://github.com/rust-num/num-traits/pull/21
[22]: https://github.com/rust-num/num-traits/pull/22
[23]: https://github.com/rust-num/num-traits/pull/23


# Prior releases

No prior release notes were kept.  Thanks all the same to the many
contributors that have made this crate what it is!