auto merge of #19378 : japaric/rust/no-as-slice, r=alexcrichton

Now that we have an overloaded comparison (`==`) operator, and that `Vec`/`String` deref to `[T]`/`str` on method calls, many `as_slice()`/`as_mut_slice()`/`to_string()` calls have become redundant. This patch removes them. These were the most common patterns:

- `assert_eq(test_output.as_slice(), "ground truth")` -> `assert_eq(test_output, "ground truth")`
- `assert_eq(test_output, "ground truth".to_string())` -> `assert_eq(test_output, "ground truth")`
- `vec.as_mut_slice().sort()` -> `vec.sort()`
- `vec.as_slice().slice(from, to)` -> `vec.slice(from_to)`

---

Note that e.g. `a_string.push_str(b_string.as_slice())` has been left untouched in this PR, since we first need to settle down whether we want to favor the `&*b_string` or the `b_string[]` notation.

This is rebased on top of #19167

cc @alexcrichton @aturon

Author: bors

src/liballoc/arc.rs

@@ -521,7 +521,7 @@ mod tests {
     #[test]
     fn show_arc() {
         let a = Arc::new(5u32);
-        assert!(format!("{}", a).as_slice() == "5")
+        assert!(format!("{}", a) == "5")
     }
 
     // Make sure deriving works with Arc<T>

src/liballoc/boxed.rs

@@ -169,14 +169,14 @@ mod test {
         let b = box Test as Box<Any>;
         let a_str = a.to_str();
         let b_str = b.to_str();
-        assert_eq!(a_str.as_slice(), "Box<Any>");
-        assert_eq!(b_str.as_slice(), "Box<Any>");
+        assert_eq!(a_str, "Box<Any>");
+        assert_eq!(b_str, "Box<Any>");
 
         let a = &8u as &Any;
         let b = &Test as &Any;
         let s = format!("{}", a);
-        assert_eq!(s.as_slice(), "&Any");
+        assert_eq!(s, "&Any");
         let s = format!("{}", b);
-        assert_eq!(s.as_slice(), "&Any");
+        assert_eq!(s, "&Any");
     }
 }

src/libcollections/binary_heap.rs

@@ -485,7 +485,7 @@ impl<T: Ord> BinaryHeap<T> {
         let mut end = q.len();
         while end > 1 {
             end -= 1;
-            q.data.as_mut_slice().swap(0, end);
+            q.data.swap(0, end);
             q.siftdown_range(0, end)
         }
         q.into_vec()
@@ -769,8 +769,8 @@ mod tests {
         v.sort();
         data.sort();
 
-        assert_eq!(v.as_slice(), data.as_slice());
-        assert_eq!(heap.into_sorted_vec().as_slice(), data.as_slice());
+        assert_eq!(v, data);
+        assert_eq!(heap.into_sorted_vec(), data);
     }
 
     #[test]
@@ -812,7 +812,7 @@ mod tests {
     fn test_from_iter() {
         let xs = vec!(9u, 8, 7, 6, 5, 4, 3, 2, 1);
 
-        let mut q: BinaryHeap<uint> = xs.as_slice().iter().rev().map(|&x| x).collect();
+        let mut q: BinaryHeap<uint> = xs.iter().rev().map(|&x| x).collect();
 
         for &x in xs.iter() {
             assert_eq!(q.pop().unwrap(), x);

src/libcollections/bit.rs

@@ -1692,10 +1692,10 @@ mod tests {
     #[test]
     fn test_to_str() {
         let zerolen = Bitv::new();
-        assert_eq!(zerolen.to_string().as_slice(), "");
+        assert_eq!(zerolen.to_string(), "");
 
         let eightbits = Bitv::with_capacity(8u, false);
-        assert_eq!(eightbits.to_string().as_slice(), "00000000")
+        assert_eq!(eightbits.to_string(), "00000000")
     }
 
     #[test]
@@ -1718,7 +1718,7 @@ mod tests {
         let mut b = bitv::Bitv::with_capacity(2, false);
         b.set(0, true);
         b.set(1, false);
-        assert_eq!(b.to_string().as_slice(), "10");
+        assert_eq!(b.to_string(), "10");
     }
 
     #[test]
@@ -2029,7 +2029,7 @@ mod tests {
     fn test_from_bytes() {
         let bitv = from_bytes(&[0b10110110, 0b00000000, 0b11111111]);
         let str = format!("{}{}{}", "10110110", "00000000", "11111111");
-        assert_eq!(bitv.to_string().as_slice(), str.as_slice());
+        assert_eq!(bitv.to_string(), str);
     }
 
     #[test]
@@ -2048,7 +2048,7 @@ mod tests {
     fn test_from_bools() {
         let bools = vec![true, false, true, true];
         let bitv: Bitv = bools.iter().map(|n| *n).collect();
-        assert_eq!(bitv.to_string().as_slice(), "1011");
+        assert_eq!(bitv.to_string(), "1011");
     }
 
     #[test]
@@ -2207,7 +2207,7 @@ mod tests {
 
         let expected = [3, 5, 11, 77];
         let actual = a.intersection(&b).collect::<Vec<uint>>();
-        assert_eq!(actual.as_slice(), expected.as_slice());
+        assert_eq!(actual, expected);
     }
 
     #[test]
@@ -2226,7 +2226,7 @@ mod tests {
 
         let expected = [1, 5, 500];
         let actual = a.difference(&b).collect::<Vec<uint>>();
-        assert_eq!(actual.as_slice(), expected.as_slice());
+        assert_eq!(actual, expected);
     }
 
     #[test]
@@ -2247,7 +2247,7 @@ mod tests {
 
         let expected = [1, 5, 11, 14, 220];
         let actual = a.symmetric_difference(&b).collect::<Vec<uint>>();
-        assert_eq!(actual.as_slice(), expected.as_slice());
+        assert_eq!(actual, expected);
     }
 
     #[test]
@@ -2272,7 +2272,7 @@ mod tests {
 
         let expected = [1, 3, 5, 9, 11, 13, 19, 24, 160, 200];
         let actual = a.union(&b).collect::<Vec<uint>>();
-        assert_eq!(actual.as_slice(), expected.as_slice());
+        assert_eq!(actual, expected);
     }
 
     #[test]
@@ -2660,7 +2660,7 @@ mod tests {
         s.insert(10);
         s.insert(50);
         s.insert(2);
-        assert_eq!("{1, 2, 10, 50}".to_string(), s.to_string());
+        assert_eq!("{1, 2, 10, 50}", s.to_string());
     }
 
     fn rng() -> rand::IsaacRng {

src/libcollections/btree/node.rs

@@ -158,43 +158,43 @@ impl <K, V> Node<K, V> {
     /// Swap the given key-value pair with the key-value pair stored in the node's index,
     /// without checking bounds.
     pub unsafe fn unsafe_swap(&mut self, index: uint, key: &mut K, val: &mut V) {
-        mem::swap(self.keys.as_mut_slice().unsafe_mut(index), key);
-        mem::swap(self.vals.as_mut_slice().unsafe_mut(index), val);
+        mem::swap(self.keys.unsafe_mut(index), key);
+        mem::swap(self.vals.unsafe_mut(index), val);
     }
 
     /// Get the node's key mutably without any bounds checks.
     pub unsafe fn unsafe_key_mut(&mut self, index: uint) -> &mut K {
-        self.keys.as_mut_slice().unsafe_mut(index)
+        self.keys.unsafe_mut(index)
     }
 
     /// Get the node's value at the given index
     pub fn val(&self, index: uint) -> Option<&V> {
-        self.vals.as_slice().get(index)
+        self.vals.get(index)
     }
 
     /// Get the node's value at the given index
     pub fn val_mut(&mut self, index: uint) -> Option<&mut V> {
-        self.vals.as_mut_slice().get_mut(index)
+        self.vals.get_mut(index)
     }
 
     /// Get the node's value mutably without any bounds checks.
     pub unsafe fn unsafe_val_mut(&mut self, index: uint) -> &mut V {
-        self.vals.as_mut_slice().unsafe_mut(index)
+        self.vals.unsafe_mut(index)
     }
 
     /// Get the node's edge at the given index
     pub fn edge(&self, index: uint) -> Option<&Node<K,V>> {
-        self.edges.as_slice().get(index)
+        self.edges.get(index)
     }
 
     /// Get the node's edge mutably at the given index
     pub fn edge_mut(&mut self, index: uint) -> Option<&mut Node<K,V>> {
-        self.edges.as_mut_slice().get_mut(index)
+        self.edges.get_mut(index)
     }
 
     /// Get the node's edge mutably without any bounds checks.
     pub unsafe fn unsafe_edge_mut(&mut self, index: uint) -> &mut Node<K,V> {
-        self.edges.as_mut_slice().unsafe_mut(index)
+        self.edges.unsafe_mut(index)
     }
 
     /// Pop an edge off the end of the node
@@ -281,8 +281,8 @@ impl <K, V> Node<K, V> {
     pub fn iter<'a>(&'a self) -> Traversal<'a, K, V> {
         let is_leaf = self.is_leaf();
         Traversal {
-            elems: self.keys.as_slice().iter().zip(self.vals.as_slice().iter()),
-            edges: self.edges.as_slice().iter(),
+            elems: self.keys.iter().zip(self.vals.iter()),
+            edges: self.edges.iter(),
             head_is_edge: true,
             tail_is_edge: true,
             has_edges: !is_leaf,
@@ -292,8 +292,8 @@ impl <K, V> Node<K, V> {
     pub fn iter_mut<'a>(&'a mut self) -> MutTraversal<'a, K, V> {
         let is_leaf = self.is_leaf();
         MutTraversal {
-            elems: self.keys.as_slice().iter().zip(self.vals.as_mut_slice().iter_mut()),
-            edges: self.edges.as_mut_slice().iter_mut(),
+            elems: self.keys.iter().zip(self.vals.iter_mut()),
+            edges: self.edges.iter_mut(),
             head_is_edge: true,
             tail_is_edge: true,
             has_edges: !is_leaf,
@@ -477,8 +477,8 @@ fn split<T>(left: &mut Vec<T>) -> Vec<T> {
     let left_len = len - right_len;
     let mut right = Vec::with_capacity(left.capacity());
     unsafe {
-        let left_ptr = left.as_slice().unsafe_get(left_len) as *const _;
-        let right_ptr = right.as_mut_slice().as_mut_ptr();
+        let left_ptr = left.unsafe_get(left_len) as *const _;
+        let right_ptr = right.as_mut_ptr();
         ptr::copy_nonoverlapping_memory(right_ptr, left_ptr, right_len);
         left.set_len(left_len);
         right.set_len(right_len);

src/libcollections/btree/set.rs

@@ -580,7 +580,7 @@ mod test {
 
         let set_str = format!("{}", set);
 
-        assert!(set_str == "{1, 2}".to_string());
-        assert_eq!(format!("{}", empty), "{}".to_string());
+        assert!(set_str == "{1, 2}");
+        assert_eq!(format!("{}", empty), "{}");
     }
 }

src/libcollections/dlist.rs

@@ -926,7 +926,7 @@ mod tests {
         let mut m = list_from(v.as_slice());
         m.prepend(list_from(u.as_slice()));
         check_links(&m);
-        u.extend(v.as_slice().iter().map(|&b| b));
+        u.extend(v.iter().map(|&b| b));
         assert_eq!(u.len(), m.len());
         for elt in u.into_iter() {
             assert_eq!(m.pop_front(), Some(elt))
@@ -1133,7 +1133,7 @@ mod tests {
         spawn(proc() {
             check_links(&n);
             let a: &[_] = &[&1,&2,&3];
-            assert_eq!(a, n.iter().collect::<Vec<&int>>().as_slice());
+            assert_eq!(a, n.iter().collect::<Vec<&int>>());
         });
     }
 
@@ -1224,12 +1224,12 @@ mod tests {
     #[test]
     fn test_show() {
         let list: DList<int> = range(0i, 10).collect();
-        assert!(list.to_string().as_slice() == "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
+        assert!(list.to_string() == "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
 
         let list: DList<&str> = vec!["just", "one", "test", "more"].iter()
                                                                    .map(|&s| s)
                                                                    .collect();
-        assert!(list.to_string().as_slice() == "[just, one, test, more]");
+        assert!(list.to_string() == "[just, one, test, more]");
     }
 
     #[cfg(test)]

src/libcollections/enum_set.rs

@@ -288,11 +288,11 @@ mod test {
     #[test]
     fn test_show() {
         let mut e = EnumSet::new();
-        assert_eq!("{}", e.to_string().as_slice());
+        assert_eq!("{}", e.to_string());
         e.insert(A);
-        assert_eq!("{A}", e.to_string().as_slice());
+        assert_eq!("{A}", e.to_string());
         e.insert(C);
-        assert_eq!("{A, C}", e.to_string().as_slice());
+        assert_eq!("{A, C}", e.to_string());
     }
 
     #[test]

src/libcollections/ring_buf.rs

@@ -1246,15 +1246,15 @@ mod tests {
         }
         {
             let b: &[_] = &[&0,&1,&2,&3,&4];
-            assert_eq!(d.iter().collect::<Vec<&int>>().as_slice(), b);
+            assert_eq!(d.iter().collect::<Vec<&int>>(), b);
         }
 
         for i in range(6i, 9) {
             d.push_front(i);
         }
         {
             let b: &[_] = &[&8,&7,&6,&0,&1,&2,&3,&4];
-            assert_eq!(d.iter().collect::<Vec<&int>>().as_slice(), b);
+            assert_eq!(d.iter().collect::<Vec<&int>>(), b);
         }
 
         let mut it = d.iter();
@@ -1277,14 +1277,14 @@ mod tests {
         }
         {
             let b: &[_] = &[&4,&3,&2,&1,&0];
-            assert_eq!(d.iter().rev().collect::<Vec<&int>>().as_slice(), b);
+            assert_eq!(d.iter().rev().collect::<Vec<&int>>(), b);
         }
 
         for i in range(6i, 9) {
             d.push_front(i);
         }
         let b: &[_] = &[&4,&3,&2,&1,&0,&6,&7,&8];
-        assert_eq!(d.iter().rev().collect::<Vec<&int>>().as_slice(), b);
+        assert_eq!(d.iter().rev().collect::<Vec<&int>>(), b);
     }
 
     #[test]
@@ -1495,12 +1495,12 @@ mod tests {
     #[test]
     fn test_show() {
         let ringbuf: RingBuf<int> = range(0i, 10).collect();
-        assert!(format!("{}", ringbuf).as_slice() == "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
+        assert!(format!("{}", ringbuf) == "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]");
 
         let ringbuf: RingBuf<&str> = vec!["just", "one", "test", "more"].iter()
                                                                         .map(|&s| s)
                                                                         .collect();
-        assert!(format!("{}", ringbuf).as_slice() == "[just, one, test, more]");
+        assert!(format!("{}", ringbuf) == "[just, one, test, more]");
     }
 
     #[test]