Remove unused Step methods

src/libcore/iter/range.rs

@@ -22,9 +22,6 @@
            reason = "likely to be replaced by finer-grained traits",
            issue = "42168")]
 pub trait Step: PartialOrd + Sized {
-    /// Steps `self` if possible.
-    fn step(&self, by: &Self) -> Option<Self>;
-
     /// Returns the number of steps between two step objects. The count is
     /// inclusive of `start` and exclusive of `end`.
     ///
@@ -35,9 +32,6 @@ pub trait Step: PartialOrd + Sized {
     /// Same as `steps_between`, but with a `by` of 1
     fn steps_between_by_one(start: &Self, end: &Self) -> Option<usize>;
 
-    /// Tests whether this step is negative or not (going backwards)
-    fn is_negative(&self) -> bool;
-
     /// Replaces this step with `1`, returning itself
     fn replace_one(&mut self) -> Self;
 
@@ -57,10 +51,6 @@ pub trait Step: PartialOrd + Sized {
                    reason = "likely to be replaced by finer-grained traits",
                    issue = "42168")]
         impl Step for $t {
-            #[inline]
-            fn step(&self, by: &$t) -> Option<$t> {
-                (*self).checked_add(*by)
-            }
             #[inline]
             #[allow(trivial_numeric_casts)]
             fn steps_between(start: &$t, end: &$t, by: &$t) -> Option<usize> {
@@ -79,11 +69,6 @@ fn steps_between(start: &$t, end: &$t, by: &$t) -> Option<usize> {
                 }
             }
 
-            #[inline]
-            fn is_negative(&self) -> bool {
-                false
-            }
-
             #[inline]
             fn replace_one(&mut self) -> Self {
                 mem::replace(self, 1)
@@ -117,10 +102,6 @@ fn steps_between_by_one(start: &Self, end: &Self) -> Option<usize> {
                    reason = "likely to be replaced by finer-grained traits",
                    issue = "42168")]
         impl Step for $t {
-            #[inline]
-            fn step(&self, by: &$t) -> Option<$t> {
-                (*self).checked_add(*by)
-            }
             #[inline]
             #[allow(trivial_numeric_casts)]
             fn steps_between(start: &$t, end: &$t, by: &$t) -> Option<usize> {
@@ -150,11 +131,6 @@ fn steps_between(start: &$t, end: &$t, by: &$t) -> Option<usize> {
                 }
             }
 
-            #[inline]
-            fn is_negative(&self) -> bool {
-                *self < 0
-            }
-
             #[inline]
             fn replace_one(&mut self) -> Self {
                 mem::replace(self, 1)
@@ -189,21 +165,11 @@ fn steps_between_by_one(start: &Self, end: &Self) -> Option<usize> {
                    reason = "likely to be replaced by finer-grained traits",
                    issue = "42168")]
         impl Step for $t {
-            #[inline]
-            fn step(&self, by: &$t) -> Option<$t> {
-                (*self).checked_add(*by)
-            }
             #[inline]
             fn steps_between(_a: &$t, _b: &$t, _by: &$t) -> Option<usize> {
                 None
             }
 
-            #[inline]
-            #[allow(unused_comparisons)]
-            fn is_negative(&self) -> bool {
-                *self < 0
-            }
-
             #[inline]
             fn replace_one(&mut self) -> Self {
                 mem::replace(self, 1)