Add a libm feature for Float

Author: cuviper

Cargo.toml

@@ -37,3 +37,4 @@ default-features = false
 [features]
 default = ["std"]
 std = ["num-traits/std"]
+libm = ["num-traits/libm"]

README.md

@@ -27,9 +27,9 @@ version = "0.3"
 default-features = false
 ```
 
-Features based on `Float` types are only available when `std` is enabled. Where
-possible, `FloatCore` is used instead.  Formatting complex numbers only supports
-format width when `std` is enabled.
+Features based on `Float` types are only available when `std` or `libm` is
+enabled. Where possible, `FloatCore` is used instead.  Formatting complex
+numbers only supports format width when `std` is enabled.
 
 ## Releases
 

src/lib.rs

@@ -32,7 +32,7 @@ use std::error::Error;
 
 use num_traits::{Inv, MulAdd, Num, One, Pow, Signed, Zero};
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 use num_traits::float::Float;
 use num_traits::float::FloatCore;
 
@@ -159,7 +159,7 @@ impl<T: Clone + Signed> Complex<T> {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 impl<T: Clone + Float> Complex<T> {
     /// Calculate |self|
     #[inline]
@@ -1604,7 +1604,7 @@ mod test {
         }
     }
 
-    #[cfg(feature = "std")]
+    #[cfg(any(feature = "std", feature = "libm"))]
     mod float {
         use super::*;
         use num_traits::{Float, Pow};
@@ -2265,7 +2265,7 @@ mod test {
         }
 
         #[test]
-        #[cfg(feature = "std")]
+        #[cfg(any(feature = "std", feature = "libm"))]
         fn test_mul_add_float() {
             assert_eq!(_05_05i.mul_add(_05_05i, _0_0i), _05_05i * _05_05i + _0_0i);
             assert_eq!(_05_05i * _05_05i + _0_0i, _05_05i.mul_add(_05_05i, _0_0i));

src/pow.rs

@@ -1,7 +1,7 @@
 use super::Complex;
 
 use core::ops::Neg;
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 use num_traits::Float;
 use num_traits::{Num, One, Pow};
 
@@ -85,7 +85,7 @@ pow_impl!(u128, i128);
 
 macro_rules! powf_impl {
     ($F:ty) => {
-        #[cfg(feature = "std")]
+        #[cfg(any(feature = "std", feature = "libm"))]
         impl<'a, T: Float> Pow<$F> for &'a Complex<T>
         where
             $F: Into<T>,
@@ -98,7 +98,7 @@ macro_rules! powf_impl {
             }
         }
 
-        #[cfg(feature = "std")]
+        #[cfg(any(feature = "std", feature = "libm"))]
         impl<'a, 'b, T: Float> Pow<&'b $F> for &'a Complex<T>
         where
             $F: Into<T>,
@@ -111,7 +111,7 @@ macro_rules! powf_impl {
             }
         }
 
-        #[cfg(feature = "std")]
+        #[cfg(any(feature = "std", feature = "libm"))]
         impl<T: Float> Pow<$F> for Complex<T>
         where
             $F: Into<T>,
@@ -124,7 +124,7 @@ macro_rules! powf_impl {
             }
         }
 
-        #[cfg(feature = "std")]
+        #[cfg(any(feature = "std", feature = "libm"))]
         impl<'b, T: Float> Pow<&'b $F> for Complex<T>
         where
             $F: Into<T>,
@@ -145,7 +145,7 @@ powf_impl!(f64);
 // These blanket impls are OK, because both the target type and the trait parameter would be
 // foreign to anyone else trying to implement something that would overlap, raising E0117.
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 impl<'a, T: Float> Pow<Complex<T>> for &'a Complex<T> {
     type Output = Complex<T>;
 
@@ -155,7 +155,7 @@ impl<'a, T: Float> Pow<Complex<T>> for &'a Complex<T> {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 impl<'a, 'b, T: Float> Pow<&'b Complex<T>> for &'a Complex<T> {
     type Output = Complex<T>;
 
@@ -165,7 +165,7 @@ impl<'a, 'b, T: Float> Pow<&'b Complex<T>> for &'a Complex<T> {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 impl<T: Float> Pow<Complex<T>> for Complex<T> {
     type Output = Complex<T>;
 
@@ -175,7 +175,7 @@ impl<T: Float> Pow<Complex<T>> for Complex<T> {
     }
 }
 
-#[cfg(feature = "std")]
+#[cfg(any(feature = "std", feature = "libm"))]
 impl<'b, T: Float> Pow<&'b Complex<T>> for Complex<T> {
     type Output = Complex<T>;