Auto merge of #9614 - danieleades:refactor/closures-and-iterators, r=Eh2406

tidy some closures and iterators

Author: bors

src/cargo/core/compiler/custom_build.rs

@@ -299,7 +299,7 @@ fn build_work(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Job> {
 
     let extra_link_arg = cx.bcx.config.cli_unstable().extra_link_arg;
     let nightly_features_allowed = cx.bcx.config.nightly_features_allowed;
-    let targets: Vec<Target> = unit.pkg.targets().iter().cloned().collect();
+    let targets: Vec<Target> = unit.pkg.targets().to_vec();
     // Need a separate copy for the fresh closure.
     let targets_fresh = targets.clone();
 

src/cargo/core/compiler/fingerprint.rs

@@ -1320,12 +1320,7 @@ fn calculate_normal(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Finger
     let metadata = util::hash_u64((&m.authors, &m.description, &m.homepage, &m.repository));
     let mut config = 0u64;
     if unit.mode.is_doc() && cx.bcx.config.cli_unstable().rustdoc_map {
-        config = config.wrapping_add(
-            cx.bcx
-                .config
-                .doc_extern_map()
-                .map_or(0, |map| util::hash_u64(map)),
-        );
+        config = config.wrapping_add(cx.bcx.config.doc_extern_map().map_or(0, util::hash_u64));
     }
     if let Some(allow_features) = &cx.bcx.config.cli_unstable().allow_features {
         config = config.wrapping_add(util::hash_u64(allow_features));

src/cargo/core/compiler/job_queue.rs

@@ -1127,8 +1127,7 @@ impl<'cfg> DrainState<'cfg> {
             .bcx
             .unit_graph
             .keys()
-            .filter(|unit| unit.pkg.name() == "diesel" && !unit.features.is_empty())
-            .next()
+            .find(|unit| unit.pkg.name() == "diesel" && !unit.features.is_empty())
         {
             Some(u) => u,
             // Unlikely due to features.

src/cargo/core/compiler/timings.rs

@@ -529,7 +529,7 @@ impl<'cfg> Timings<'cfg> {
                     target: ut.target.clone(),
                     start: round(ut.start),
                     duration: round(ut.duration),
-                    rmeta_time: ut.rmeta_time.map(|t| round(t)),
+                    rmeta_time: ut.rmeta_time.map(round),
                     unlocked_units,
                     unlocked_rmeta_units,
                 }

src/cargo/ops/cargo_compile.rs

@@ -568,7 +568,7 @@ pub fn create_bcx<'a, 'cfg>(
             // the target is a binary. Binary crates get their private items
             // documented by default.
             if rustdoc_document_private_items || unit.target.is_bin() {
-                let mut args = extra_args.take().unwrap_or_else(|| vec![]);
+                let mut args = extra_args.take().unwrap_or_default();
                 args.push("--document-private-items".into());
                 extra_args = Some(args);
             }