removing redundant closures in the whole project

Author: Grzegorz

clippy_dev/src/lib.rs

@@ -47,7 +47,7 @@ impl Lint {
             name: name.to_lowercase(),
             group: group.to_string(),
             desc: NL_ESCAPE_RE.replace(&desc.replace("\\\"", "\""), "").to_string(),
-            deprecation: deprecation.map(|d| d.to_string()),
+            deprecation: deprecation.map(std::string::ToString::to_string),
             module: module.to_string(),
         }
     }
@@ -178,7 +178,7 @@ fn lint_files() -> impl Iterator<Item = walkdir::DirEntry> {
     // Otherwise we would not collect all the lints, for example in `clippy_lints/src/methods/`.
     WalkDir::new("../clippy_lints/src")
         .into_iter()
-        .filter_map(|f| f.ok())
+        .filter_map(std::result::Result::ok)
         .filter(|f| f.path().extension() == Some(OsStr::new("rs")))
 }
 

clippy_lints/src/attrs.rs

@@ -326,7 +326,7 @@ fn check_clippy_lint_names(cx: &LateContext<'_, '_>, items: &[NestedMetaItem]) {
                     lint.span,
                     &format!("unknown clippy lint: clippy::{}", name),
                     |db| {
-                        if name.as_str().chars().any(|c| c.is_uppercase()) {
+                        if name.as_str().chars().any(char::is_uppercase) {
                             let name_lower = name.as_str().to_lowercase();
                             match lint_store.check_lint_name(
                                 &name_lower,

clippy_lints/src/cargo_common_metadata.rs

@@ -53,7 +53,7 @@ fn is_empty_str(value: &Option<String>) -> bool {
 
 fn is_empty_vec(value: &[String]) -> bool {
     // This works because empty iterators return true
-    value.iter().all(|v| v.is_empty())
+    value.iter().all(std::string::String::is_empty)
 }
 
 pub struct Pass;

clippy_lints/src/lib.rs

@@ -267,7 +267,7 @@ pub fn read_conf(reg: &rustc_plugin::Registry<'_>) -> Conf {
                 }
             });
 
-            let (conf, errors) = utils::conf::read(file_name.as_ref().map(|p| p.as_ref()));
+            let (conf, errors) = utils::conf::read(file_name.as_ref().map(std::convert::AsRef::as_ref));
 
             // all conf errors are non-fatal, we just use the default conf in case of error
             for error in errors {

clippy_lints/src/methods/mod.rs

@@ -829,7 +829,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
 
         let (method_names, arg_lists) = method_calls(expr, 2);
         let method_names: Vec<LocalInternedString> = method_names.iter().map(|s| s.as_str()).collect();
-        let method_names: Vec<&str> = method_names.iter().map(|s| s.as_ref()).collect();
+        let method_names: Vec<&str> = method_names.iter().map(std::convert::AsRef::as_ref).collect();
 
         match method_names.as_slice() {
             ["unwrap", "get"] => lint_get_unwrap(cx, expr, arg_lists[1], false),
@@ -1695,7 +1695,7 @@ fn derefs_to_slice(cx: &LateContext<'_, '_>, expr: &hir::Expr, ty: Ty<'_>) -> Op
 
     if let hir::ExprKind::MethodCall(ref path, _, ref args) = expr.node {
         if path.ident.name == "iter" && may_slice(cx, cx.tables.expr_ty(&args[0])) {
-            sugg::Sugg::hir_opt(cx, &args[0]).map(|sugg| sugg.addr())
+            sugg::Sugg::hir_opt(cx, &args[0]).map(sugg::Sugg::addr)
         } else {
             None
         }

clippy_lints/src/non_expressive_names.rs

@@ -241,7 +241,7 @@ impl<'a, 'tcx, 'b> SimilarNamesNameVisitor<'a, 'tcx, 'b> {
                         // or too many chars differ (x_foo, y_boo) or (xfoo, yboo)
                         continue;
                     }
-                    split_at = interned_name.chars().next().map(|c| c.len_utf8());
+                    split_at = interned_name.chars().next().map(char::len_utf8);
                 }
             }
             span_lint_and_then(

clippy_lints/src/utils/conf.rs

@@ -14,7 +14,7 @@ use toml;
 pub fn file_from_args(
     args: &[source_map::Spanned<ast::NestedMetaItemKind>],
 ) -> Result<Option<path::PathBuf>, (&'static str, source_map::Span)> {
-    for arg in args.iter().filter_map(|a| a.meta_item()) {
+    for arg in args.iter().filter_map(syntax::source_map::Spanned::meta_item) {
         if arg.name() == "conf_file" {
             return match arg.node {
                 ast::MetaItemKind::Word | ast::MetaItemKind::List(_) => {

clippy_lints/src/utils/mod.rs

@@ -142,7 +142,10 @@ pub fn match_def_path(tcx: TyCtxt<'_, '_, '_>, def_id: DefId, path: &[&str]) ->
 pub fn get_def_path(tcx: TyCtxt<'_, '_, '_>, def_id: DefId) -> Vec<&'static str> {
     let mut apb = AbsolutePathBuffer { names: vec![] };
     tcx.push_item_path(&mut apb, def_id, false);
-    apb.names.iter().map(|n| n.get()).collect()
+    apb.names
+        .iter()
+        .map(syntax_pos::symbol::LocalInternedString::get)
+        .collect()
 }
 
 /// Check if type is struct, enum or union type with given def path.

rustc_tools_util/src/lib.rs

@@ -9,8 +9,8 @@ macro_rules! get_version_info {
         let crate_name = String::from(env!("CARGO_PKG_NAME"));
 
         let host_compiler = $crate::get_channel();
-        let commit_hash = option_env!("GIT_HASH").map(|s| s.to_string());
-        let commit_date = option_env!("COMMIT_DATE").map(|s| s.to_string());
+        let commit_hash = option_env!("GIT_HASH").map(str::to_string);
+        let commit_date = option_env!("COMMIT_DATE").map(str::to_string);
 
         VersionInfo {
             major,

src/driver.rs

@@ -47,7 +47,7 @@ fn arg_value<'a>(
 fn test_arg_value() {
     let args: Vec<_> = ["--bar=bar", "--foobar", "123", "--foo"]
         .iter()
-        .map(|s| s.to_string())
+        .map(std::string::ToString::to_string)
         .collect();
 
     assert_eq!(arg_value(None, "--foobar", |_| true), None);
@@ -84,7 +84,7 @@ pub fn main() {
             let sys_root_arg = arg_value(&orig_args, "--sysroot", |_| true);
             let have_sys_root_arg = sys_root_arg.is_some();
             let sys_root = sys_root_arg
-                .map(|s| s.to_string())
+                .map(std::string::ToString::to_string)
                 .or_else(|| std::env::var("SYSROOT").ok())
                 .or_else(|| {
                     let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));

tests/missing-test-files.rs

@@ -32,7 +32,7 @@ fn explore_directory(dir: &Path) -> Vec<String> {
     let mut missing_files: Vec<String> = Vec::new();
     let mut current_file = String::new();
     let mut files: Vec<DirEntry> = fs::read_dir(dir).unwrap().filter_map(Result::ok).collect();
-    files.sort_by_key(|e| e.path());
+    files.sort_by_key(std::fs::DirEntry::path);
     for entry in &files {
         let path = entry.path();
         if path.is_dir() {

tests/ui/map_clone.fixed

@@ -3,6 +3,7 @@
 #![allow(clippy::iter_cloned_collect)]
 #![allow(clippy::clone_on_copy)]
 #![allow(clippy::missing_docs_in_private_items)]
+#![allow(clippy::redundant_closure)]
 
 fn main() {
     let _: Vec<i8> = vec![5_i8; 6].iter().cloned().collect();

tests/ui/map_clone.rs

@@ -3,6 +3,7 @@
 #![allow(clippy::iter_cloned_collect)]
 #![allow(clippy::clone_on_copy)]
 #![allow(clippy::missing_docs_in_private_items)]
+#![allow(clippy::redundant_closure)]
 
 fn main() {
     let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();

tests/ui/map_clone.stderr

@@ -1,25 +1,25 @@
 error: You are using an explicit closure for cloning elements
-  --> $DIR/map_clone.rs:8:22
+  --> $DIR/map_clone.rs:9:22
    |
 LL |     let _: Vec<i8> = vec![5_i8; 6].iter().map(|x| *x).collect();
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![5_i8; 6].iter().cloned()`
    |
    = note: `-D clippy::map-clone` implied by `-D warnings`
 
 error: You are using an explicit closure for cloning elements
-  --> $DIR/map_clone.rs:9:26
+  --> $DIR/map_clone.rs:10:26
    |
 LL |     let _: Vec<String> = vec![String::new()].iter().map(|x| x.clone()).collect();
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![String::new()].iter().cloned()`
 
 error: You are using an explicit closure for cloning elements
-  --> $DIR/map_clone.rs:10:23
+  --> $DIR/map_clone.rs:11:23
    |
 LL |     let _: Vec<u32> = vec![42, 43].iter().map(|&x| x).collect();
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Consider calling the dedicated `cloned` method: `vec![42, 43].iter().cloned()`
 
 error: You are needlessly cloning iterator elements
-  --> $DIR/map_clone.rs:22:29
+  --> $DIR/map_clone.rs:23:29
    |
 LL |     let _ = std::env::args().map(|v| v.clone());
    |                             ^^^^^^^^^^^^^^^^^^^ help: Remove the map call