Stop considering _ as a keyword

Author: GuillaumeGomez

src/librustdoc/html/highlight.rs

@@ -785,8 +785,11 @@ impl<'a> Iterator for TokenIter<'a> {
 
 /// Classifies into identifier class; returns `None` if this is a non-keyword identifier.
 fn get_real_ident_class(text: &str, allow_path_keywords: bool) -> Option<Class> {
-    let ignore: &[&str] =
-        if allow_path_keywords { &["self", "Self", "super", "crate"] } else { &["self", "Self"] };
+    let ignore: &[&str] = if allow_path_keywords {
+        &["self", "Self", "super", "crate", "_"]
+    } else {
+        &["self", "Self", "_"]
+    };
     if ignore.contains(&text) {
         return None;
     }

src/librustdoc/html/highlight/fixtures/sample.html

@@ -16,10 +16,10 @@
 #[cfg(target_os = <span class="string">"windows"</span>)]
 </span><span class="kw">fn </span>main() -&gt; () {
     <span class="kw">let </span>foo = <span class="bool-val">true </span>&amp;&amp; <span class="bool-val">false </span>|| <span class="bool-val">true</span>;
-    <span class="kw">let _</span>: <span class="kw-2">*const </span>() = <span class="number">0</span>;
-    <span class="kw">let _ </span>= <span class="kw-2">&amp;</span>foo;
-    <span class="kw">let _ </span>= &amp;&amp;foo;
-    <span class="kw">let _ </span>= <span class="kw-2">*</span>foo;
+    <span class="kw">let </span>_: <span class="kw-2">*const </span>() = <span class="number">0</span>;
+    <span class="kw">let </span>_ = <span class="kw-2">&amp;</span>foo;
+    <span class="kw">let </span>_ = &amp;&amp;foo;
+    <span class="kw">let </span>_ = <span class="kw-2">*</span>foo;
     <span class="macro">mac!</span>(foo, <span class="kw-2">&amp;mut </span>bar);
     <span class="macro">assert!</span>(<span class="self">self</span>.length &lt; N &amp;&amp; index &lt;= <span class="self">self</span>.length);
     ::std::env::var(<span class="string">"gateau"</span>).is_ok();