Move functions remaining in num to num-traits

Fixes #102.

src/lib.rs

@@ -78,10 +78,10 @@ pub use num_complex::Complex;
 pub use num_integer::Integer;
 pub use num_iter::{range, range_inclusive, range_step, range_step_inclusive};
 pub use num_traits::{Num, Zero, One, Signed, Unsigned, Bounded,
+                     one, zero, abs, abs_sub, signum,
                      Saturating, CheckedAdd, CheckedSub, CheckedMul, CheckedDiv,
-                     PrimInt, Float, ToPrimitive, FromPrimitive, NumCast, cast};
-
-use std::ops::{Mul};
+                     PrimInt, Float, ToPrimitive, FromPrimitive, NumCast, cast,
+                     pow, checked_pow};
 
 #[cfg(feature = "num-bigint")]
 pub mod bigint {
@@ -109,114 +109,3 @@ pub mod traits {
 pub mod rational {
     pub use num_rational::*;
 }
-
-/// Returns the additive identity, `0`.
-#[inline(always)] pub fn zero<T: Zero>() -> T { Zero::zero() }
-
-/// Returns the multiplicative identity, `1`.
-#[inline(always)] pub fn one<T: One>() -> T { One::one() }
-
-/// Computes the absolute value.
-///
-/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`
-///
-/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
-#[inline(always)]
-pub fn abs<T: Signed>(value: T) -> T {
-    value.abs()
-}
-
-/// The positive difference of two numbers.
-///
-/// Returns zero if `x` is less than or equal to `y`, otherwise the difference
-/// between `x` and `y` is returned.
-#[inline(always)]
-pub fn abs_sub<T: Signed>(x: T, y: T) -> T {
-    x.abs_sub(&y)
-}
-
-/// Returns the sign of the number.
-///
-/// For `f32` and `f64`:
-///
-/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
-/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
-/// * `NaN` if the number is `NaN`
-///
-/// For signed integers:
-///
-/// * `0` if the number is zero
-/// * `1` if the number is positive
-/// * `-1` if the number is negative
-#[inline(always)] pub fn signum<T: Signed>(value: T) -> T { value.signum() }
-
-/// Raises a value to the power of exp, using exponentiation by squaring.
-///
-/// # Example
-///
-/// ```rust
-/// use num;
-///
-/// assert_eq!(num::pow(2i8, 4), 16);
-/// assert_eq!(num::pow(6u8, 3), 216);
-/// ```
-#[inline]
-pub fn pow<T: Clone + One + Mul<T, Output = T>>(mut base: T, mut exp: usize) -> T {
-    if exp == 0 { return T::one() }
-
-    while exp & 1 == 0 {
-        base = base.clone() * base;
-        exp >>= 1;
-    }
-    if exp == 1 { return base }
-
-    let mut acc = base.clone();
-    while exp > 1 {
-        exp >>= 1;
-        base = base.clone() * base;
-        if exp & 1 == 1 {
-            acc = acc * base.clone();
-        }
-    }
-    acc
-}
-
-/// Raises a value to the power of exp, returning `None` if an overflow occurred.
-///
-/// Otherwise same as the `pow` function.
-///
-/// # Example
-///
-/// ```rust
-/// use num;
-///
-/// assert_eq!(num::checked_pow(2i8, 4), Some(16));
-/// assert_eq!(num::checked_pow(7i8, 8), None);
-/// assert_eq!(num::checked_pow(7u32, 8), Some(5_764_801));
-/// ```
-#[inline]
-pub fn checked_pow<T: Clone + One + CheckedMul>(mut base: T, mut exp: usize) -> Option<T> {
-    if exp == 0 { return Some(T::one()) }
-
-    macro_rules! optry {
-        ( $ expr : expr ) => {
-            if let Some(val) = $expr { val } else { return None }
-        }
-    }
-
-    while exp & 1 == 0 {
-        base = optry!(base.checked_mul(&base));
-        exp >>= 1;
-    }
-    if exp == 1 { return Some(base) }
-
-    let mut acc = base.clone();
-    while exp > 1 {
-        exp >>= 1;
-        base = optry!(base.checked_mul(&base));
-        if exp & 1 == 1 {
-            acc = optry!(acc.checked_mul(&base));
-        }
-    }
-    Some(acc)
-}

traits/src/identities.rs

@@ -93,3 +93,12 @@ one_impl!(i64,   1i64);
 
 one_impl!(f32, 1.0f32);
 one_impl!(f64, 1.0f64);
+
+
+// Some helper functions provided for backwards compatibility.
+
+/// Returns the additive identity, `0`.
+#[inline(always)] pub fn zero<T: Zero>() -> T { Zero::zero() }
+
+/// Returns the multiplicative identity, `1`.
+#[inline(always)] pub fn one<T: One>() -> T { One::one() }

traits/src/lib.rs

@@ -14,12 +14,13 @@ use std::ops::{Add, Sub, Mul, Div, Rem};
 
 pub use bounds::Bounded;
 pub use float::Float;
-pub use identities::{Zero, One};
+pub use identities::{Zero, One, zero, one};
 pub use ops::checked::*;
 pub use ops::saturating::Saturating;
-pub use sign::{Signed, Unsigned};
+pub use sign::{Signed, Unsigned, abs, abs_sub, signum};
 pub use cast::*;
 pub use int::PrimInt;
+pub use pow::{pow, checked_pow};
 
 pub mod identities;
 pub mod sign;
@@ -28,6 +29,7 @@ pub mod bounds;
 pub mod float;
 pub mod cast;
 pub mod int;
+pub mod pow;
 
 /// The base trait for numeric types
 pub trait Num: PartialEq + Zero + One

traits/src/pow.rs

@@ -0,0 +1,73 @@
+use std::ops::Mul;
+use {One, CheckedMul};
+
+/// Raises a value to the power of exp, using exponentiation by squaring.
+///
+/// # Example
+///
+/// ```rust
+/// use num_traits::pow;
+///
+/// assert_eq!(pow(2i8, 4), 16);
+/// assert_eq!(pow(6u8, 3), 216);
+/// ```
+#[inline]
+pub fn pow<T: Clone + One + Mul<T, Output = T>>(mut base: T, mut exp: usize) -> T {
+    if exp == 0 { return T::one() }
+
+    while exp & 1 == 0 {
+        base = base.clone() * base;
+        exp >>= 1;
+    }
+    if exp == 1 { return base }
+
+    let mut acc = base.clone();
+    while exp > 1 {
+        exp >>= 1;
+        base = base.clone() * base;
+        if exp & 1 == 1 {
+            acc = acc * base.clone();
+        }
+    }
+    acc
+}
+
+/// Raises a value to the power of exp, returning `None` if an overflow occurred.
+///
+/// Otherwise same as the `pow` function.
+///
+/// # Example
+///
+/// ```rust
+/// use num_traits::checked_pow;
+///
+/// assert_eq!(checked_pow(2i8, 4), Some(16));
+/// assert_eq!(checked_pow(7i8, 8), None);
+/// assert_eq!(checked_pow(7u32, 8), Some(5_764_801));
+/// ```
+#[inline]
+pub fn checked_pow<T: Clone + One + CheckedMul>(mut base: T, mut exp: usize) -> Option<T> {
+    if exp == 0 { return Some(T::one()) }
+
+    macro_rules! optry {
+        ( $ expr : expr ) => {
+            if let Some(val) = $expr { val } else { return None }
+        }
+    }
+
+    while exp & 1 == 0 {
+        base = optry!(base.checked_mul(&base));
+        exp >>= 1;
+    }
+    if exp == 1 { return Some(base) }
+
+    let mut acc = base.clone();
+    while exp > 1 {
+        exp >>= 1;
+        base = optry!(base.checked_mul(&base));
+        if exp & 1 == 1 {
+            acc = optry!(acc.checked_mul(&base));
+        }
+    }
+    Some(acc)
+}

traits/src/sign.rs

@@ -114,6 +114,40 @@ macro_rules! signed_float_impl {
 signed_float_impl!(f32, f32::NAN, f32::INFINITY, f32::NEG_INFINITY);
 signed_float_impl!(f64, f64::NAN, f64::INFINITY, f64::NEG_INFINITY);
 
+/// Computes the absolute value.
+///
+/// For `f32` and `f64`, `NaN` will be returned if the number is `NaN`
+///
+/// For signed integers, `::MIN` will be returned if the number is `::MIN`.
+#[inline(always)]
+pub fn abs<T: Signed>(value: T) -> T {
+    value.abs()
+}
+
+/// The positive difference of two numbers.
+///
+/// Returns zero if `x` is less than or equal to `y`, otherwise the difference
+/// between `x` and `y` is returned.
+#[inline(always)]
+pub fn abs_sub<T: Signed>(x: T, y: T) -> T {
+    x.abs_sub(&y)
+}
+
+/// Returns the sign of the number.
+///
+/// For `f32` and `f64`:
+///
+/// * `1.0` if the number is positive, `+0.0` or `INFINITY`
+/// * `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
+/// * `NaN` if the number is `NaN`
+///
+/// For signed integers:
+///
+/// * `0` if the number is zero
+/// * `1` if the number is positive
+/// * `-1` if the number is negative
+#[inline(always)] pub fn signum<T: Signed>(value: T) -> T { value.signum() }
+
 /// A trait for values which cannot be negative
 pub trait Unsigned: Num {}