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, 2 insertions, 2 deletions

diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index df25daa3ca1..10563c61e14 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -231,7 +231,7 @@ pub fn render(w: &mut fmt::Formatter, s: &str, print_toc: bool) -> fmt::Result {
         };
 
         // Transform the contents of the header into a hyphenated string
-        let id = s.as_slice().words().map(|s| s.to_ascii_lower())
+        let id = s.words().map(|s| s.to_ascii_lower())
             .collect::<Vec<String>>().connect("-");
 
         // This is a terrible hack working around how hoedown gives us rendered
@@ -393,7 +393,7 @@ impl LangString {
         let mut seen_other_tags = false;
         let mut data = LangString::all_false();
 
-        let mut tokens = string.as_slice().split(|c: char|
+        let mut tokens = string.split(|c: char|
             !(c == '_' || c == '-' || c.is_alphanumeric())
         );