auto merge of #13597 : bjz/rust/float-api, r=brson

This pull request:

- Merges the `Round` trait into the `Float` trait, continuing issue #10387.
- Has floating point functions take their parameters by value.
- Cleans up the formatting and organisation in the definition and implementations of the `Float` trait.

More information on the breaking changes can be found in the commit messages.

Author: bors

src/doc/guide-tasks.md

@@ -306,7 +306,7 @@ be distributed on the available cores.
 fn partial_sum(start: uint) -> f64 {
     let mut local_sum = 0f64;
     for num in range(start*100000, (start+1)*100000) {
-        local_sum += (num as f64 + 1.0).powf(&-2.0);
+        local_sum += (num as f64 + 1.0).powf(-2.0);
     }
     local_sum
 }
@@ -343,7 +343,7 @@ extern crate sync;
 use sync::Arc;
 
 fn pnorm(nums: &[f64], p: uint) -> f64 {
-    nums.iter().fold(0.0, |a,b| a+(*b).powf(&(p as f64)) ).powf(&(1.0 / (p as f64)))
+    nums.iter().fold(0.0, |a, b| a + b.powf(p as f64)).powf(1.0 / (p as f64))
 }
 
 fn main() {

src/libnum/complex.rs

@@ -82,15 +82,15 @@ impl<T: Clone + Float> Cmplx<T> {
     /// Calculate |self|
     #[inline]
     pub fn norm(&self) -> T {
-        self.re.hypot(&self.im)
+        self.re.hypot(self.im)
     }
 }
 
 impl<T: Clone + Float> Cmplx<T> {
     /// Calculate the principal Arg of self.
     #[inline]
     pub fn arg(&self) -> T {
-        self.im.atan2(&self.re)
+        self.im.atan2(self.re)
     }
     /// Convert to polar form (r, theta), such that `self = r * exp(i
     /// * theta)`

src/libnum/rational.rs

@@ -15,7 +15,7 @@ use Integer;
 use std::cmp;
 use std::fmt;
 use std::from_str::FromStr;
-use std::num::{Zero,One,ToStrRadix,FromStrRadix,Round};
+use std::num::{Zero, One, ToStrRadix, FromStrRadix};
 use bigint::{BigInt, BigUint, Sign, Plus, Minus};
 
 /// Represents the ratio between 2 numbers.
@@ -113,6 +113,40 @@ impl<T: Clone + Integer + Ord>
     pub fn recip(&self) -> Ratio<T> {
         Ratio::new_raw(self.denom.clone(), self.numer.clone())
     }
+
+    pub fn floor(&self) -> Ratio<T> {
+        if *self < Zero::zero() {
+            Ratio::from_integer((self.numer - self.denom + One::one()) / self.denom)
+        } else {
+            Ratio::from_integer(self.numer / self.denom)
+        }
+    }
+
+    pub fn ceil(&self) -> Ratio<T> {
+        if *self < Zero::zero() {
+            Ratio::from_integer(self.numer / self.denom)
+        } else {
+            Ratio::from_integer((self.numer + self.denom - One::one()) / self.denom)
+        }
+    }
+
+    #[inline]
+    pub fn round(&self) -> Ratio<T> {
+        if *self < Zero::zero() {
+            Ratio::from_integer((self.numer - self.denom + One::one()) / self.denom)
+        } else {
+            Ratio::from_integer((self.numer + self.denom - One::one()) / self.denom)
+        }
+    }
+
+    #[inline]
+    pub fn trunc(&self) -> Ratio<T> {
+        Ratio::from_integer(self.numer / self.denom)
+    }
+
+    pub fn fract(&self) -> Ratio<T> {
+        Ratio::new_raw(self.numer % self.denom, self.denom.clone())
+    }
 }
 
 impl Ratio<BigInt> {
@@ -238,45 +272,6 @@ impl<T: Clone + Integer + Ord>
 impl<T: Clone + Integer + Ord>
     Num for Ratio<T> {}
 
-/* Utils */
-impl<T: Clone + Integer + Ord>
-    Round for Ratio<T> {
-
-    fn floor(&self) -> Ratio<T> {
-        if *self < Zero::zero() {
-            Ratio::from_integer((self.numer - self.denom + One::one()) / self.denom)
-        } else {
-            Ratio::from_integer(self.numer / self.denom)
-        }
-    }
-
-    fn ceil(&self) -> Ratio<T> {
-        if *self < Zero::zero() {
-            Ratio::from_integer(self.numer / self.denom)
-        } else {
-            Ratio::from_integer((self.numer + self.denom - One::one()) / self.denom)
-        }
-    }
-
-    #[inline]
-    fn round(&self) -> Ratio<T> {
-        if *self < Zero::zero() {
-            Ratio::from_integer((self.numer - self.denom + One::one()) / self.denom)
-        } else {
-            Ratio::from_integer((self.numer + self.denom - One::one()) / self.denom)
-        }
-    }
-
-    #[inline]
-    fn trunc(&self) -> Ratio<T> {
-        Ratio::from_integer(self.numer / self.denom)
-    }
-
-    fn fract(&self) -> Ratio<T> {
-        Ratio::new_raw(self.numer % self.denom, self.denom.clone())
-    }
-}
-
 /* String conversions */
 impl<T: fmt::Show> fmt::Show for Ratio<T> {
     /// Renders as `numer/denom`.
@@ -636,19 +631,19 @@ mod test {
 
         // f32
         test(3.14159265359f32, ("13176795", "4194304"));
-        test(2f32.powf(&100.), ("1267650600228229401496703205376", "1"));
-        test(-2f32.powf(&100.), ("-1267650600228229401496703205376", "1"));
-        test(1.0 / 2f32.powf(&100.), ("1", "1267650600228229401496703205376"));
+        test(2f32.powf(100.), ("1267650600228229401496703205376", "1"));
+        test(-2f32.powf(100.), ("-1267650600228229401496703205376", "1"));
+        test(1.0 / 2f32.powf(100.), ("1", "1267650600228229401496703205376"));
         test(684729.48391f32, ("1369459", "2"));
         test(-8573.5918555f32, ("-4389679", "512"));
 
         // f64
         test(3.14159265359f64, ("3537118876014453", "1125899906842624"));
-        test(2f64.powf(&100.), ("1267650600228229401496703205376", "1"));
-        test(-2f64.powf(&100.), ("-1267650600228229401496703205376", "1"));
+        test(2f64.powf(100.), ("1267650600228229401496703205376", "1"));
+        test(-2f64.powf(100.), ("-1267650600228229401496703205376", "1"));
         test(684729.48391f64, ("367611342500051", "536870912"));
         test(-8573.5918555, ("-4713381968463931", "549755813888"));
-        test(1.0 / 2f64.powf(&100.), ("1", "1267650600228229401496703205376"));
+        test(1.0 / 2f64.powf(100.), ("1", "1267650600228229401496703205376"));
     }
 
     #[test]

src/librand/distributions/gamma.rs

@@ -147,7 +147,7 @@ impl IndependentSample<f64> for GammaSmallShape {
     fn ind_sample<R: Rng>(&self, rng: &mut R) -> f64 {
         let Open01(u) = rng.gen::<Open01<f64>>();
 
-        self.large_shape.ind_sample(rng) * u.powf(&self.inv_shape)
+        self.large_shape.ind_sample(rng) * u.powf(self.inv_shape)
     }
 }
 impl IndependentSample<f64> for GammaLargeShape {