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 

1 files changed, 8 insertions, 8 deletions

diff --git a/src/libstd/num/strconv.rs b/src/libstd/num/strconv.rs
index b42286c0308..c87f40f351b 100644
--- a/src/libstd/num/strconv.rs
+++ b/src/libstd/num/strconv.rs
@@ -428,28 +428,28 @@ mod tests {
     #[test]
     fn test_int_to_str_overflow() {
         let mut i8_val: i8 = 127_i8;
-        assert_eq!(i8_val.to_string(), "127".to_string());
+        assert_eq!(i8_val.to_string(), "127");
 
         i8_val += 1 as i8;
-        assert_eq!(i8_val.to_string(), "-128".to_string());
+        assert_eq!(i8_val.to_string(), "-128");
 
         let mut i16_val: i16 = 32_767_i16;
-        assert_eq!(i16_val.to_string(), "32767".to_string());
+        assert_eq!(i16_val.to_string(), "32767");
 
         i16_val += 1 as i16;
-        assert_eq!(i16_val.to_string(), "-32768".to_string());
+        assert_eq!(i16_val.to_string(), "-32768");
 
         let mut i32_val: i32 = 2_147_483_647_i32;
-        assert_eq!(i32_val.to_string(), "2147483647".to_string());
+        assert_eq!(i32_val.to_string(), "2147483647");
 
         i32_val += 1 as i32;
-        assert_eq!(i32_val.to_string(), "-2147483648".to_string());
+        assert_eq!(i32_val.to_string(), "-2147483648");
 
         let mut i64_val: i64 = 9_223_372_036_854_775_807_i64;
-        assert_eq!(i64_val.to_string(), "9223372036854775807".to_string());
+        assert_eq!(i64_val.to_string(), "9223372036854775807");
 
         i64_val += 1 as i64;
-        assert_eq!(i64_val.to_string(), "-9223372036854775808".to_string());
+        assert_eq!(i64_val.to_string(), "-9223372036854775808");
     }
 }