Auto merge of #5280 - klausi:clippy-191-trvials, r=matklad

chore(clippy): Simplify minor stuff found by clippy

Executed clippy 0.0.191, fixed the trivial stuff.
Filed rust-lang/rust-clippy#2615 for all the format_err!() false positives.

Author: bors

src/cargo/core/dependency.rs

@@ -186,7 +186,7 @@ impl Dependency {
     }
 
     pub fn new_override(name: &str, source_id: &SourceId) -> Dependency {
-        assert!(name.len() > 0);
+        assert!(!name.is_empty());
         Dependency {
             inner: Rc::new(Inner {
                 name: InternedString::new(name),

src/cargo/core/resolver/context.rs

@@ -340,7 +340,7 @@ struct Requirements<'a> {
 }
 
 impl<'r> Requirements<'r> {
-    fn new<'a>(summary: &'a Summary) -> Requirements<'a> {
+    fn new(summary: &Summary) -> Requirements {
         Requirements {
             summary,
             deps: HashMap::new(),
@@ -390,7 +390,7 @@ impl<'r> Requirements<'r> {
                 ),
                 _ => {}
             }
-            self.require_value(&fv)?;
+            self.require_value(fv)?;
         }
         Ok(())
     }

src/cargo/core/resolver/mod.rs

@@ -432,7 +432,7 @@ fn activate_deps_loop(
                             .remaining_siblings
                             .clone()
                             .filter_map(|(_, (ref new_dep, _, _))| {
-                                past_conflicting_activations.conflicting(&cx, &new_dep)
+                                past_conflicting_activations.conflicting(&cx, new_dep)
                             })
                             .next()
                         {
@@ -818,7 +818,7 @@ fn compatible(a: &semver::Version, b: &semver::Version) -> bool {
 ///
 /// Read <https://github.com/rust-lang/cargo/pull/4834>
 /// For several more detailed explanations of the logic here.
-fn find_candidate<'a>(
+fn find_candidate(
     backtrack_stack: &mut Vec<BacktrackFrame>,
     parent: &Summary,
     conflicting_activations: &HashMap<PackageId, ConflictReason>,

src/cargo/core/resolver/types.rs

@@ -134,8 +134,8 @@ impl<'a> RegistryQueryer<'a> {
             let previous_cmp = a_in_previous.cmp(&b_in_previous).reverse();
             match previous_cmp {
                 Ordering::Equal => {
-                    let cmp = a.summary.version().cmp(&b.summary.version());
-                    if self.minimal_versions == true {
+                    let cmp = a.summary.version().cmp(b.summary.version());
+                    if self.minimal_versions {
                         // Lower version ordered first.
                         cmp
                     } else {

src/cargo/core/summary.rs

@@ -130,7 +130,7 @@ impl PartialEq for Summary {
 // and creates FeatureValues for each feature.
 fn build_feature_map(
     features: BTreeMap<String, Vec<String>>,
-    dependencies: &Vec<Dependency>,
+    dependencies: &[Dependency],
 ) -> CargoResult<FeatureMap> {
     use self::FeatureValue::*;
     let mut map = BTreeMap::new();
@@ -145,9 +145,9 @@ fn build_feature_map(
 
             // Find data for the referenced dependency...
             let dep_data = {
-                let dep_name = match &val {
-                    &Feature(_) => "",
-                    &Crate(ref dep_name) | &CrateFeature(ref dep_name, _) => dep_name,
+                let dep_name = match val {
+                    Feature(_) => "",
+                    Crate(ref dep_name) | CrateFeature(ref dep_name, _) => dep_name,
                 };
                 dependencies.iter().find(|d| *d.name() == *dep_name)
             };

src/cargo/ops/cargo_new.rs

@@ -318,7 +318,7 @@ pub fn new(opts: &NewOptions, config: &Config) -> CargoResult<()> {
 
     let mkopts = MkOptions {
         version_control: opts.version_control,
-        path: &path,
+        path,
         name,
         source_files: vec![plan_new_source_file(opts.kind.is_bin(), name.to_string())],
         bin: opts.kind.is_bin(),
@@ -341,12 +341,12 @@ pub fn init(opts: &NewOptions, config: &Config) -> CargoResult<()> {
         bail!("`cargo init` cannot be run on existing Cargo projects")
     }
 
-    let name = get_name(&path, opts)?;
+    let name = get_name(path, opts)?;
     check_name(name, opts)?;
 
     let mut src_paths_types = vec![];
 
-    detect_source_paths_and_types(&path, name, &mut src_paths_types)?;
+    detect_source_paths_and_types(path, name, &mut src_paths_types)?;
 
     if src_paths_types.is_empty() {
         src_paths_types.push(plan_new_source_file(opts.kind.is_bin(), name.to_string()));
@@ -444,37 +444,40 @@ fn mk(config: &Config, opts: &MkOptions) -> CargoResult<()> {
 
     match vcs {
         VersionControl::Git => {
-            if !fs::metadata(&path.join(".git")).is_ok() {
+            if !path.join(".git").exists() {
                 GitRepo::init(path, config.cwd())?;
             }
-            let ignore = match fs::metadata(&path.join(".gitignore")) {
-                Ok(_) => format!("\n{}", ignore),
-                _ => ignore,
+            let ignore = if path.join(".gitignore").exists() {
+                format!("\n{}", ignore)
+            } else {
+                ignore
             };
             paths::append(&path.join(".gitignore"), ignore.as_bytes())?;
         }
         VersionControl::Hg => {
-            if !fs::metadata(&path.join(".hg")).is_ok() {
+            if !path.join(".hg").exists() {
                 HgRepo::init(path, config.cwd())?;
             }
-            let hgignore = match fs::metadata(&path.join(".hgignore")) {
-                Ok(_) => format!("\n{}", hgignore),
-                _ => hgignore,
+            let hgignore = if path.join(".hgignore").exists() {
+                format!("\n{}", hgignore)
+            } else {
+                hgignore
             };
             paths::append(&path.join(".hgignore"), hgignore.as_bytes())?;
         }
         VersionControl::Pijul => {
-            if !fs::metadata(&path.join(".pijul")).is_ok() {
+            if !path.join(".pijul").exists() {
                 PijulRepo::init(path, config.cwd())?;
             }
-            let ignore = match fs::metadata(&path.join(".ignore")) {
-                Ok(_) => format!("\n{}", ignore),
-                _ => ignore,
+            let ignore = if path.join(".ignore").exists() {
+                format!("\n{}", ignore)
+            } else {
+                ignore
             };
             paths::append(&path.join(".ignore"), ignore.as_bytes())?;
         }
         VersionControl::Fossil => {
-            if !fs::metadata(&path.join(".fossil")).is_ok() {
+            if path.join(".fossil").exists() {
                 FossilRepo::init(path, config.cwd())?;
             }
         }

src/cargo/ops/cargo_package.rs

@@ -47,7 +47,7 @@ pub fn package(ws: &Workspace, opts: &PackageOpts) -> CargoResult<Option<FileLoc
             .iter()
             .map(|file| util::without_prefix(file, root).unwrap().to_path_buf())
             .collect();
-        if include_lockfile(&pkg) {
+        if include_lockfile(pkg) {
             list.push("Cargo.lock".into());
         }
         list.sort();

src/cargo/ops/cargo_run.rs

@@ -18,7 +18,7 @@ pub fn run(
         Packages::Packages(ref xs) => match xs.len() {
             0 => ws.current()?,
             1 => ws.members()
-                .find(|pkg| &*pkg.name() == xs[0])
+                .find(|pkg| *pkg.name() == xs[0])
                 .ok_or_else(|| {
                     format_err!("package `{}` is not a member of the workspace", xs[0])
                 })?,

src/cargo/ops/cargo_rustc/context/compilation_files.rs

@@ -384,7 +384,7 @@ fn compute_metadata<'a, 'cfg>(
         && (unit.target.is_dylib() || unit.target.is_cdylib()
             || (unit.target.is_bin() && cx.target_triple().starts_with("wasm32-")))
         && unit.pkg.package_id().source_id().is_path()
-        && !__cargo_default_lib_metadata.is_ok()
+        && __cargo_default_lib_metadata.is_err()
     {
         return None;
     }

src/cargo/ops/cargo_rustc/mod.rs

@@ -603,13 +603,13 @@ fn link_targets<'a, 'cfg>(
                 }
             };
             destinations.push(dst.display().to_string());
-            hardlink_or_copy(&src, &dst)?;
+            hardlink_or_copy(src, dst)?;
             if let Some(ref path) = export_dir {
                 if !path.exists() {
                     fs::create_dir_all(path)?;
                 }
 
-                hardlink_or_copy(&src, &path.join(dst.file_name().unwrap()))?;
+                hardlink_or_copy(src, &path.join(dst.file_name().unwrap()))?;
             }
         }