diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs index 86e6352d132..33df175bfc5 100644 --- a/library/core/src/num/f32.rs +++ b/library/core/src/num/f32.rs @@ -441,6 +441,32 @@ pub const fn is_finite(self) -> bool { self.abs_private() < Self::INFINITY } + /// Returns `true` if the number is [subnormal]. + /// + /// ``` + /// #![feature(is_subnormal)] + /// let min = f32::MIN_POSITIVE; // 1.17549435e-38f32 + /// let max = f32::MAX; + /// let lower_than_min = 1.0e-40_f32; + /// let zero = 0.0_f32; + /// + /// assert!(!min.is_subnormal()); + /// assert!(!max.is_subnormal()); + /// + /// assert!(!zero.is_subnormal()); + /// assert!(!f32::NAN.is_subnormal()); + /// assert!(!f32::INFINITY.is_subnormal()); + /// // Values between `0` and `min` are Subnormal. + /// assert!(lower_than_min.is_subnormal()); + /// ``` + /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number + #[unstable(feature = "is_subnormal", issue = "79288")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + #[inline] + pub const fn is_subnormal(self) -> bool { + matches!(self.classify(), FpCategory::Subnormal) + } + /// Returns `true` if the number is neither zero, infinite, /// [subnormal], or `NaN`. /// diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs index 9b1405b479f..b85e8deb6d2 100644 --- a/library/core/src/num/f64.rs +++ b/library/core/src/num/f64.rs @@ -440,6 +440,32 @@ pub const fn is_finite(self) -> bool { self.abs_private() < Self::INFINITY } + /// Returns `true` if the number is [subnormal]. + /// + /// ``` + /// #![feature(is_subnormal)] + /// let min = f64::MIN_POSITIVE; // 2.2250738585072014e-308_f64 + /// let max = f64::MAX; + /// let lower_than_min = 1.0e-308_f64; + /// let zero = 0.0_f64; + /// + /// assert!(!min.is_subnormal()); + /// assert!(!max.is_subnormal()); + /// + /// assert!(!zero.is_subnormal()); + /// assert!(!f64::NAN.is_subnormal()); + /// assert!(!f64::INFINITY.is_subnormal()); + /// // Values between `0` and `min` are Subnormal. + /// assert!(lower_than_min.is_subnormal()); + /// ``` + /// [subnormal]: https://en.wikipedia.org/wiki/Denormal_number + #[unstable(feature = "is_subnormal", issue = "79288")] + #[rustc_const_unstable(feature = "const_float_classify", issue = "72505")] + #[inline] + pub const fn is_subnormal(self) -> bool { + matches!(self.classify(), FpCategory::Subnormal) + } + /// Returns `true` if the number is neither zero, infinite, /// [subnormal], or `NaN`. ///