Auto merge of #81993 - flip1995:clippyup, r=Manishearth

[rust.git] / clippy_lints / src / map_unit_fn.rs

diff --git a/clippy_lints/src/map_unit_fn.rs b/clippy_lints/src/map_unit_fn.rs
index 1f9ae8c931a1ee3aea3cbb5e683987a31ce71252..01126e86199b41172d5087cba7fc7192cf4cf5c3 100644 (file)
--- a/clippy_lints/src/map_unit_fn.rs
+++ b/clippy_lints/src/map_unit_fn.rs
@@ -6,10 +6,11 @@
 use rustc_middle::ty::{self, Ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::source_map::Span;
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// **What it does:** Checks for usage of `option.map(f)` where f is a function
-    /// or closure that returns the unit type.
+    /// or closure that returns the unit type `()`.
     ///
     /// **Why is this bad?** Readability, this can be written more clearly with
     /// an if let statement
@@ -51,7 +52,7 @@
 
 declare_clippy_lint! {
     /// **What it does:** Checks for usage of `result.map(f)` where f is a function
-    /// or closure that returns the unit type.
+    /// or closure that returns the unit type `()`.
     ///
     /// **Why is this bad?** Readability, this can be written more clearly with
     /// an if let statement
@@ -130,7 +131,7 @@ fn reduce_unit_expression<'a>(cx: &LateContext<'_>, expr: &'a hir::Expr<'_>) ->
             Some(expr.span)
         },
         hir::ExprKind::Block(ref block, _) => {
-            match (&block.stmts[..], block.expr.as_ref()) {
+            match (block.stmts, block.expr.as_ref()) {
                 (&[], Some(inner_expr)) => {
                     // If block only contains an expression,
                     // reduce `{ X }` to `X`
@@ -197,7 +198,7 @@ fn let_binding_name(cx: &LateContext<'_>, var_arg: &hir::Expr<'_>) -> String {
 #[must_use]
 fn suggestion_msg(function_type: &str, map_type: &str) -> String {
     format!(
-        "called `map(f)` on an `{0}` value where `f` is a {1} that returns the unit type",
+        "called `map(f)` on an `{0}` value where `f` is a {1} that returns the unit type `()`",
         map_type, function_type
     )
 }
@@ -206,9 +207,9 @@ fn lint_map_unit_fn(cx: &LateContext<'_>, stmt: &hir::Stmt<'_>, expr: &hir::Expr
     let var_arg = &map_args[0];
 
     let (map_type, variant, lint) =
-        if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym!(option_type)) {
+        if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym::option_type) {
             ("Option", "Some", OPTION_MAP_UNIT_FN)
-        } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym!(result_type)) {
+        } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(var_arg), sym::result_type) {
             ("Result", "Ok", RESULT_MAP_UNIT_FN)
         } else {
             return;