Use a single global guard in mod real

src/real.rs

@@ -1,9 +1,8 @@
-use core::ops::Neg;
+#![cfg(any(feature = "std", feature = "libm"))]
 
-use {Num, NumCast};
+use core::ops::Neg;
 
-#[cfg(any(feature = "std", feature = "libm"))]
-use Float;
+use {Float, Num, NumCast};
 
 // NOTE: These doctests have the same issue as those in src/float.rs.
 // They're testing the inherent methods directly, and not those of `Real`.
@@ -14,14 +13,11 @@ use Float;
 /// See [this Wikipedia article](https://en.wikipedia.org/wiki/Real_data_type)
 /// for a list of data types that could meaningfully implement this trait.
 ///
-/// This trait is always available, however it requires either `std` or `libm`
-/// in order for `f32` and `f64` to implement it.
-#[cfg(any(feature = "std", feature = "libm"))]
+/// This trait is only available with the `std` feature, or with the `libm` feature otherwise.
 pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Returns the smallest finite value that this type can represent.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -33,8 +29,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the smallest positive, normalized value that this type can represent.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -46,8 +41,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns epsilon, a small positive value.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -64,8 +58,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the largest finite value that this type can represent.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -76,8 +69,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the largest integer less than or equal to a number.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 3.99;
@@ -90,8 +82,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the smallest integer greater than or equal to a number.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 3.01;
@@ -105,8 +96,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Returns the nearest integer to a number. Round half-way cases away from
     /// `0.0`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 3.3;
@@ -119,8 +109,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Return the integer part of a number.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 3.3;
@@ -133,8 +122,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the fractional part of a number.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 3.5;
@@ -150,8 +138,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Computes the absolute value of `self`. Returns `Float::nan()` if the
     /// number is `Float::nan()`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -174,8 +161,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// - `-1.0` if the number is negative, `-0.0` or `Float::neg_infinity()`
     /// - `Float::nan()` if the number is `Float::nan()`
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -191,8 +177,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Returns `true` if `self` is positive, including `+0.0`,
     /// `Float::infinity()`, and with newer versions of Rust `f64::NAN`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -210,8 +195,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Returns `true` if `self` is negative, including `-0.0`,
     /// `Float::neg_infinity()`, and with newer versions of Rust `-f64::NAN`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -232,8 +216,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Using `mul_add` can be more performant than an unfused multiply-add if
     /// the target architecture has a dedicated `fma` CPU instruction.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let m = 10.0;
@@ -249,8 +232,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Take the reciprocal (inverse) of a number, `1/x`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 2.0;
@@ -264,8 +246,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     ///
     /// Using this function is generally faster than using `powf`
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 2.0;
@@ -277,8 +258,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Raise a number to a real number power.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 2.0;
@@ -296,8 +276,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     ///
     /// If the implementing type doesn't support NaN, this method should panic if `self < 0`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let positive = 4.0;
@@ -312,8 +291,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns `e^(self)`, (the exponential function).
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let one = 1.0;
@@ -329,8 +307,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns `2^(self)`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 2.0;
@@ -348,8 +325,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     ///
     /// If `self <= 0` and this type does not support a NaN representation, this function should panic.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let one = 1.0;
@@ -369,8 +345,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     ///
     /// If `self <= 0` and this type does not support a NaN representation, this function should panic.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let ten = 10.0;
@@ -393,8 +368,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     ///
     /// If `self <= 0` and this type does not support a NaN representation, this function should panic.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let two = 2.0;
@@ -413,8 +387,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// If `self <= 0` and this type does not support a NaN representation, this function should panic.
     ///
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let ten = 10.0;
@@ -428,8 +401,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Converts radians to degrees.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use std::f64::consts;
     ///
     /// let angle = consts::PI;
@@ -442,8 +414,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Converts degrees to radians.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use std::f64::consts;
     ///
     /// let angle = 180.0_f64;
@@ -456,8 +427,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the maximum of the two numbers.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 1.0;
@@ -469,8 +439,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Returns the minimum of the two numbers.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 1.0;
@@ -485,8 +454,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// * If `self <= other`: `0:0`
     /// * Else: `self - other`
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 3.0;
@@ -502,8 +470,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Take the cubic root of a number.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 8.0;
@@ -518,8 +485,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Calculate the length of the hypotenuse of a right-angle triangle given
     /// legs of length `x` and `y`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 2.0;
@@ -534,8 +500,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Computes the sine of a number (in radians).
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -549,8 +514,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Computes the cosine of a number (in radians).
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -564,8 +528,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Computes the tangent of a number (in radians).
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -585,8 +548,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// If this type does not support a NaN representation, this function should panic
     /// if the number is outside the range [-1, 1].
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -608,8 +570,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// If this type does not support a NaN representation, this function should panic
     /// if the number is outside the range [-1, 1].
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -625,8 +586,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Computes the arctangent of a number. Return value is in radians in the
     /// range [-pi/2, pi/2];
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let f = 1.0;
@@ -645,8 +605,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// * `y >= 0`: `arctan(y/x) + pi` -> `(pi/2, pi]`
     /// * `y < 0`: `arctan(y/x) - pi` -> `(-pi, -pi/2)`
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -671,8 +630,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Simultaneously computes the sine and cosine of the number, `x`. Returns
     /// `(sin(x), cos(x))`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -690,8 +648,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// Returns `e^(self) - 1` in a way that is accurate even if the
     /// number is close to zero.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 7.0;
@@ -711,8 +668,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     /// If this type does not support a NaN representation, this function should panic
     /// if `self-1 <= 0`.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -727,8 +683,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Hyperbolic sine function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -746,8 +701,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Hyperbolic cosine function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -765,8 +719,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Hyperbolic tangent function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -784,8 +737,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Inverse hyperbolic sine function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 1.0;
@@ -799,8 +751,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Inverse hyperbolic cosine function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     ///
     /// let x = 1.0;
@@ -814,8 +765,7 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
 
     /// Inverse hyperbolic tangent function.
     ///
-    #[cfg_attr(any(feature = "std", feature = "libm"), doc = " ```")]
-    #[cfg_attr(not(any(feature = "std", feature = "libm")), doc = " ```ignore")]
+    /// ```
     /// use num_traits::real::Real;
     /// use std::f64;
     ///
@@ -829,7 +779,6 @@ pub trait Real: Num + Copy + NumCast + PartialOrd + Neg<Output = Self> {
     fn atanh(self) -> Self;
 }
 
-#[cfg(any(feature = "std", feature = "libm"))]
 impl<T: Float> Real for T {
     forward! {
         Float::min_value() -> Self;