Remove usage the unstable Step trait

components/range/lib.rs

@@ -2,8 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#![feature(step_trait)]
-
 #![deny(unsafe_code)]
 
 extern crate heapsize;
@@ -13,8 +11,6 @@ extern crate num_traits;
 
 use std::cmp::{self, max, min};
 use std::fmt;
-use std::iter;
-use std::marker::PhantomData;
 use std::ops;
 
 pub trait Int:
@@ -27,6 +23,7 @@ pub trait Int:
     fn one() -> Self;
     fn max_value() -> Self;
     fn from_usize(n: usize) -> Option<Self>;
+    fn to_usize(self) -> usize;
 }
 impl Int for isize {
     #[inline]
@@ -37,6 +34,8 @@ impl Int for isize {
     fn max_value() -> isize { ::std::isize::MAX }
     #[inline]
     fn from_usize(n: usize) -> Option<isize> { num_traits::NumCast::from(n) }
+    #[inline]
+    fn to_usize(self) -> usize { num_traits::NumCast::from(self).unwrap() }
 }
 impl Int for usize {
     #[inline]
@@ -47,6 +46,8 @@ impl Int for usize {
     fn max_value() -> usize { ::std::usize::MAX }
     #[inline]
     fn from_usize(n: usize) -> Option<usize> { Some(n) }
+    #[inline]
+    fn to_usize(self) -> usize { self }
 }
 
 /// An index type to be used by a `Range`
@@ -89,7 +90,7 @@ macro_rules! int_range_index {
             }
         }
 
-        impl RangeIndex for $Self_ {
+        impl $crate::RangeIndex for $Self_ {
             type Index = $T;
             #[inline]
             fn new(x: $T) -> $Self_ {
@@ -111,6 +112,8 @@ macro_rules! int_range_index {
             fn max_value() -> $Self_ { $Self_($crate::Int::max_value()) }
             #[inline]
             fn from_usize(n: usize) -> Option<$Self_> { $crate::Int::from_usize(n).map($Self_) }
+            #[inline]
+            fn to_usize(self) -> usize { self.to_usize() }
         }
 
         impl ::std::ops::Add<$Self_> for $Self_ {
@@ -156,27 +159,37 @@ impl<I: RangeIndex> fmt::Debug for Range<I> {
 }
 
 /// An iterator over each index in a range
-pub struct EachIndex<T, I> {
-    it: ops::Range<T>,
-    phantom: PhantomData<I>,
+pub struct EachIndex<I: RangeIndex> {
+    start: I,
+    stop: I,
 }
 
-pub fn each_index<T: Int, I: RangeIndex<Index=T>>(start: I, stop: I) -> EachIndex<T, I> {
-    EachIndex { it: start.get()..stop.get(), phantom: PhantomData }
+pub fn each_index<I: RangeIndex>(start: I, stop: I) -> EachIndex<I> {
+    EachIndex { start, stop }
 }
 
-impl<T: Int, I: RangeIndex<Index=T>> Iterator for EachIndex<T, I>
-where T: Int + iter::Step, for<'a> &'a T: ops::Add<&'a T, Output = T> {
+impl<I: RangeIndex> Iterator for EachIndex<I> {
     type Item = I;
 
     #[inline]
     fn next(&mut self) -> Option<I> {
-        self.it.next().map(RangeIndex::new)
+        if self.start < self.stop {
+            let next = self.start;
+            self.start = next + I::one();
+            Some(next)
+        } else {
+            None
+        }
     }
 
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
-        self.it.size_hint()
+        if self.start < self.stop {
+            let len = (self.stop - self.start).to_usize();
+            (len, Some(len))
+        } else {
+            (0, Some(0))
+        }
     }
 }
 
@@ -317,10 +330,10 @@ impl<I: RangeIndex> Range<I> {
 }
 
 /// Methods for `Range`s with indices based on integer values
-impl<T: Int, I: RangeIndex<Index=T>> Range<I> {
+impl<I: RangeIndex> Range<I> {
     /// Returns an iterater that increments over `[begin, end)`.
     #[inline]
-    pub fn each_index(&self) -> EachIndex<T, I> {
+    pub fn each_index(&self) -> EachIndex<I> {
         each_index(self.begin(), self.end())
     }
 }