auto merge of rust-lang#12321 : bjz/rust/remove-real, r=alexcrichton

This is part of the effort to simplify `std::num`, as tracked in issue rust-lang#10387. It is also a step towards a proper IEEE-754 trait (see rust-lang#12281).

src/etc/vim/syntax/rust.vim

@@ -85,7 +85,7 @@ syn keyword rustTrait Iterator DoubleEndedIterator RandomAccessIterator Cloneabl
 syn keyword rustTrait OrdIterator MutableDoubleEndedIterator ExactSize
 
 syn keyword rustTrait Algebraic Trigonometric Exponential Hyperbolic
-syn keyword rustTrait Bitwise Bounded Integer Fractional Real RealExt
+syn keyword rustTrait Bitwise Bounded Integer
 syn keyword rustTrait Num NumCast CheckedAdd CheckedSub CheckedMul CheckedDiv
 syn keyword rustTrait Orderable Signed Unsigned Round
 syn keyword rustTrait Primitive Int Float ToStrRadix ToPrimitive FromPrimitive

src/libnum/complex.rs

@@ -77,15 +77,15 @@ impl<T: Clone + Num> Cmplx<T> {
     }
 }
 
-impl<T: Clone + Real> Cmplx<T> {
+impl<T: Clone + Float> Cmplx<T> {
     /// Calculate |self|
     #[inline]
     pub fn norm(&self) -> T {
         self.re.hypot(&self.im)
     }
 }
 
-impl<T: Clone + Real> Cmplx<T> {
+impl<T: Clone + Float> Cmplx<T> {
     /// Calculate the principal Arg of self.
     #[inline]
     pub fn arg(&self) -> T {
@@ -192,7 +192,7 @@ mod test {
     #[allow(non_uppercase_statics)];
 
     use super::{Complex64, Cmplx};
-    use std::num::{Zero,One,Real};
+    use std::num::{Zero,One,Float};
 
     pub static _0_0i : Complex64 = Cmplx { re: 0.0, im: 0.0 };
     pub static _1_0i : Complex64 = Cmplx { re: 1.0, im: 0.0 };
@@ -270,9 +270,9 @@ mod test {
             assert!((c.arg() - arg).abs() < 1.0e-6)
         }
         test(_1_0i, 0.0);
-        test(_1_1i, 0.25 * Real::pi());
-        test(_neg1_1i, 0.75 * Real::pi());
-        test(_05_05i, 0.25 * Real::pi());
+        test(_1_1i, 0.25 * Float::pi());
+        test(_neg1_1i, 0.75 * Float::pi());
+        test(_05_05i, 0.25 * Float::pi());
     }
 
     #[test]