more clippy fixes

src/librustc_builtin_macros/deriving/generic/mod.rs

@@ -1056,8 +1056,9 @@ impl<'a> MethodDef<'a> {
                     self_: field,
                     other: other_fields
                         .iter_mut()
-                        .map(|l| match l.next().unwrap() {
-                            (.., ex, _) => ex,
+                        .map(|l| {
+                            let (.., ex, _) = l.next().unwrap();
+                            ex
                         })
                         .collect(),
                     attrs,

src/librustc_span/source_map.rs

@@ -370,11 +370,11 @@ impl SourceMap {
     pub fn doctest_offset_line(&self, file: &FileName, orig: usize) -> usize {
         match file {
             FileName::DocTest(_, offset) => {
-                return if *offset >= 0 {
-                    orig + *offset as usize
-                } else {
+                if *offset < 0 {
                     orig - (-(*offset)) as usize
-                };
+                } else {
+                    orig + *offset as usize
+                }
             }
             _ => orig,
         }

src/librustc_target/spec/apple_base.rs

@@ -57,7 +57,7 @@ pub fn macos_link_env_remove() -> Vec<String> {
     let mut env_remove = Vec::with_capacity(2);
     // Remove the `SDKROOT` environment variable if it's clearly set for the wrong platform, which
     // may occur when we're linking a custom build script while targeting iOS for example.
-    if let Some(sdkroot) = env::var("SDKROOT").ok() {
+    if let Ok(sdkroot) = env::var("SDKROOT") {
         if sdkroot.contains("iPhoneOS.platform") || sdkroot.contains("iPhoneSimulator.platform") {
             env_remove.push("SDKROOT".to_string())
         }

src/librustc_target/spec/apple_sdk_base.rs

@@ -43,7 +43,7 @@ pub fn get_sdk_root(sdk_name: &str) -> Result<String, String> {
     // to allow the SDK path to be set. (For clang, xcrun sets
     // SDKROOT; for rustc, the user or build system can set it, or we
     // can fall back to checking for xcrun on PATH.)
-    if let Some(sdkroot) = env::var("SDKROOT").ok() {
+    if let Ok(sdkroot) = env::var("SDKROOT") {
         let p = Path::new(&sdkroot);
         match sdk_name {
             // Ignore `SDKROOT` if it's clearly set for the wrong platform.

src/librustc_typeck/check/method/mod.rs

@@ -368,11 +368,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let fn_sig = tcx.fn_sig(def_id);
         let fn_sig = self.replace_bound_vars_with_fresh_vars(span, infer::FnCall, &fn_sig).0;
         let fn_sig = fn_sig.subst(self.tcx, substs);
-        let fn_sig = match self.normalize_associated_types_in_as_infer_ok(span, &fn_sig) {
-            InferOk { value, obligations: o } => {
-                obligations.extend(o);
-                value
-            }
+
+        let InferOk { value, obligations: o } =
+            self.normalize_associated_types_in_as_infer_ok(span, &fn_sig);
+        let fn_sig = {
+            obligations.extend(o);
+            value
         };
 
         // Register obligations for the parameters. This will include the
@@ -384,12 +385,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Note that as the method comes from a trait, it should not have
         // any late-bound regions appearing in its bounds.
         let bounds = self.tcx.predicates_of(def_id).instantiate(self.tcx, substs);
-        let bounds = match self.normalize_associated_types_in_as_infer_ok(span, &bounds) {
-            InferOk { value, obligations: o } => {
-                obligations.extend(o);
-                value
-            }
+
+        let InferOk { value, obligations: o } =
+            self.normalize_associated_types_in_as_infer_ok(span, &bounds);
+        let bounds = {
+            obligations.extend(o);
+            value
         };
+
         assert!(!bounds.has_escaping_bound_vars());
 
         let cause = traits::ObligationCause::misc(span, self.body_id);

src/librustdoc/theme.rs

@@ -234,9 +234,7 @@ pub fn load_css_paths(v: &[u8]) -> CssPath {
 }
 
 pub fn get_differences(against: &CssPath, other: &CssPath, v: &mut Vec<String>) {
-    if against.name != other.name {
-        return;
-    } else {
+    if against.name == other.name {
         for child in &against.children {
             let mut found = false;
             let mut found_working = false;