fix doc

Author: quangcito

book/src/lint_configuration.md

@@ -735,7 +735,7 @@ Minimum chars an ident can have, anything below or equal to this will be linted.
 
 
 ## `missing-docs-allow-unused`
-Whether to allow fields starting with underscore to skip documentation requirements
+Whether to allow fields starting with an underscore to skip documentation requirements
 
 **Default Value:** `false`
 

clippy_config/src/conf.rs

@@ -675,7 +675,7 @@ define_Conf! {
     /// Minimum chars an ident can have, anything below or equal to this will be linted.
     #[lints(min_ident_chars)]
     min_ident_chars_threshold: u64 = 1,
-    /// Whether to allow fields starting with underscore to skip documentation requirements
+    /// Whether to allow fields starting with an underscore to skip documentation requirements
     #[lints(missing_docs_in_private_items)]
     missing_docs_allow_unused: bool = false,
     /// Whether to **only** check for missing documentation in items visible within the current

clippy_lints/src/missing_doc.rs

@@ -48,7 +48,7 @@ pub struct MissingDoc {
     /// Whether to **only** check for missing documentation in items visible within the current
     /// crate. For example, `pub(crate)` items.
     crate_items_only: bool,
-    /// Whether to allow fields starting with underscore to skip documentation requirements
+    /// Whether to allow fields starting with an underscore to skip documentation requirements
     allow_unused: bool,
     /// Stack of whether #[doc(hidden)] is set
     /// at each level which has lint attributes.
@@ -264,7 +264,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
 
     fn check_field_def(&mut self, cx: &LateContext<'tcx>, sf: &'tcx hir::FieldDef<'_>) {
         if !sf.is_positional() {
-            // Skip checking if the field starts with underscore and allow_unused is enabled
+            // Skip checking if the field starts with an underscore and allow_unused is enabled
             if self.allow_unused && sf.ident.as_str().starts_with('_') {
                 self.prev_span = Some(sf.span);
                 return;

tests/ui-toml/missing_docs_allow_unused/missing_docs_allow_unused.rs

@@ -6,7 +6,7 @@
 struct Test {
     /// This field is documented
     field1: i32,
-    _unused: i32, // This should not trigger a warning because it starts with underscore
+    _unused: i32, // This should not trigger a warning because it starts with an underscore
     field3: i32,  //~ missing_docs_in_private_items
 }