diff --git a/clippy_lints/src/collapsible_if.rs b/clippy_lints/src/collapsible_if.rs
index 239a24b6b3c..06db5319d21 100644
--- a/clippy_lints/src/collapsible_if.rs
+++ b/clippy_lints/src/collapsible_if.rs
@@ -103,7 +103,7 @@ fn check_if(cx: &EarlyContext, expr: &ast::Expr) {
 fn check_collapsible_maybe_if_let(cx: &EarlyContext, else_: &ast::Expr) {
     if_let_chain! {[
         let ast::ExprKind::Block(ref block) = else_.node,
-        let Some(ref else_) = expr_block(block),
+        let Some(else_) = expr_block(block),
         !in_macro(else_.span),
     ], {
         match else_.node {
diff --git a/clippy_lints/src/copies.rs b/clippy_lints/src/copies.rs
index 730c0ac9633..ea7bbfe81e0 100644
--- a/clippy_lints/src/copies.rs
+++ b/clippy_lints/src/copies.rs
@@ -228,7 +228,7 @@ fn if_sequence(mut expr: &Expr) -> (SmallVector<&Expr>, SmallVector<&Block>) {
     while let ExprIf(ref cond, ref then_expr, ref else_expr) = expr.node {
         conds.push(&**cond);
         if let ExprBlock(ref block) = then_expr.node {
-            blocks.push(&block);
+            blocks.push(block);
         } else {
             panic!("ExprIf node is not an ExprBlock");
         }
diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs
index ff57afb7324..d7760a30622 100644
--- a/clippy_lints/src/loops.rs
+++ b/clippy_lints/src/loops.rs
@@ -894,7 +894,7 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
                         match def {
                             Def::Local(..) | Def::Upvar(..) => {
                                 let def_id = def.def_id();
-                                let node_id = self.cx.tcx.hir.as_local_node_id(def_id).unwrap();
+                                let node_id = self.cx.tcx.hir.as_local_node_id(def_id).expect("local/upvar are local nodes");
 
                                 let extent = self.cx.tcx.region_maps.var_scope(node_id);
                                 self.indexed.insert(seqvar.segments[0].name, Some(extent));
diff --git a/clippy_lints/src/methods.rs b/clippy_lints/src/methods.rs
index bc4c2b037e9..84897da7412 100644
--- a/clippy_lints/src/methods.rs
+++ b/clippy_lints/src/methods.rs
@@ -649,7 +649,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
                 if name == method_name &&
                    sig.decl.inputs.len() == n_args &&
                    out_type.matches(&sig.decl.output) &&
-                   self_kind.matches(&first_arg_ty, &first_arg, &self_ty, false) {
+                   self_kind.matches(first_arg_ty, first_arg, self_ty, false) {
                     span_lint(cx, SHOULD_IMPLEMENT_TRAIT, implitem.span, &format!(
                         "defining a method called `{}` on this type; consider implementing \
                          the `{}` trait or choosing a less ambiguous name", name, trait_name));
@@ -662,7 +662,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
             for &(ref conv, self_kinds) in &CONVENTIONS {
                 if_let_chain! {[
                     conv.check(&name.as_str()),
-                    !self_kinds.iter().any(|k| k.matches(&first_arg_ty, &first_arg, &self_ty, is_copy)),
+                    !self_kinds.iter().any(|k| k.matches(first_arg_ty, first_arg, self_ty, is_copy)),
                 ], {
                     let lint = if item.vis == hir::Visibility::Public {
                         WRONG_PUB_SELF_CONVENTION
diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs
index 5d3f07ecba9..e84fd196874 100644
--- a/clippy_lints/src/misc.rs
+++ b/clippy_lints/src/misc.rs
@@ -499,9 +499,9 @@ fn is_used(cx: &LateContext, expr: &Expr) -> bool {
 /// Test whether an expression is in a macro expansion (e.g. something generated by
 /// `#[derive(...)`] or the like).
 fn in_attributes_expansion(expr: &Expr) -> bool {
-    expr.span.ctxt.outer().expn_info().map(|info| {
+    expr.span.ctxt.outer().expn_info().map_or(false, |info| {
         matches!(info.callee.format, ExpnFormat::MacroAttribute(_))
-    }).unwrap_or(false)
+    })
 }
 
 /// Test whether `def` is a variable defined outside a macro.
diff --git a/clippy_lints/src/partialeq_ne_impl.rs b/clippy_lints/src/partialeq_ne_impl.rs
index 6989eb79f8e..5fee08a0c49 100644
--- a/clippy_lints/src/partialeq_ne_impl.rs
+++ b/clippy_lints/src/partialeq_ne_impl.rs
@@ -40,7 +40,8 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
         if_let_chain! {[
             let ItemImpl(_, _, _, Some(ref trait_ref), _, ref impl_items) = item.node,
             !is_automatically_derived(&*item.attrs),
-            trait_ref.path.def.def_id() == cx.tcx.lang_items.eq_trait().unwrap(),
+            let Some(eq_trait) = cx.tcx.lang_items.eq_trait(),
+            trait_ref.path.def.def_id() == eq_trait
         ], {
             for impl_item in impl_items {
                 if impl_item.name == "ne" {
diff --git a/clippy_lints/src/ranges.rs b/clippy_lints/src/ranges.rs
index aa190402f29..5b7cb9aa86f 100644
--- a/clippy_lints/src/ranges.rs
+++ b/clippy_lints/src/ranges.rs
@@ -66,7 +66,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for StepByZero {
                     let ExprMethodCall( Spanned { node: iter_name, .. }, _, ref iter_args ) = *iter,
                     iter_name == "iter",
                     // range expression in .zip() call: 0..x.len()
-                    let Some(higher::Range { start: Some(ref start), end: Some(ref end), .. }) = higher::range(zip_arg),
+                    let Some(higher::Range { start: Some(start), end: Some(end), .. }) = higher::range(zip_arg),
                     is_integer_literal(start, 0),
                     // .len() call
                     let ExprMethodCall(Spanned { node: len_name, .. }, _, ref len_args) = end.node,
diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs
index 031e3f8cf2c..16f582c77c9 100644
--- a/clippy_lints/src/returns.rs
+++ b/clippy_lints/src/returns.rs
@@ -107,7 +107,7 @@ impl ReturnPass {
 
         // we need both a let-binding stmt and an expr
         if_let_chain! {[
-            let Some(ref retexpr) = it.next_back(),
+            let Some(retexpr) = it.next_back(),
             let ast::StmtKind::Expr(ref retexpr) = retexpr.node,
             let Some(stmt) = it.next_back(),
             let ast::StmtKind::Local(ref local) = stmt.node,
diff --git a/clippy_lints/src/swap.rs b/clippy_lints/src/swap.rs
index d17b8987d2c..b2c56fe8bf3 100644
--- a/clippy_lints/src/swap.rs
+++ b/clippy_lints/src/swap.rs
@@ -115,13 +115,11 @@ fn check_manual_swap(cx: &LateContext, block: &Block) {
                 } else {
                     (false, "".to_owned(), "".to_owned())
                 }
+            } else if let (Some(first), Some(second)) = (Sugg::hir_opt(cx, lhs1), Sugg::hir_opt(cx, rhs1)) {
+                (true, format!(" `{}` and `{}`", first, second),
+                    format!("std::mem::swap({}, {})", first.mut_addr(), second.mut_addr()))
             } else {
-                 if let (Some(first), Some(second)) = (Sugg::hir_opt(cx, lhs1), Sugg::hir_opt(cx, rhs1)) {
-                    (true, format!(" `{}` and `{}`", first, second),
-                     format!("std::mem::swap({}, {})", first.mut_addr(), second.mut_addr()))
-                } else {
-                    (true, "".to_owned(), "".to_owned())
-                }
+                (true, "".to_owned(), "".to_owned())
             };
 
             let span = Span { lo: w[0].span.lo, hi: second.span.hi, ctxt: NO_EXPANSION};
diff --git a/clippy_lints/src/types.rs b/clippy_lints/src/types.rs
index de90ff323d9..005c508f123 100644
--- a/clippy_lints/src/types.rs
+++ b/clippy_lints/src/types.rs
@@ -118,7 +118,7 @@ fn check_ty(cx: &LateContext, ast_ty: &Ty) {
                     let last = last_path_segment(qpath);
                     if_let_chain! {[
                         let PathParameters::AngleBracketedParameters(ref ag) = last.parameters,
-                        let Some(ref vec) = ag.types.get(0),
+                        let Some(vec) = ag.types.get(0),
                         let TyPath(ref qpath) = vec.node,
                         let def::Def::Struct(..) = cx.tables.qpath_def(qpath, vec.id),
                         let Some(did) = opt_def_id(cx.tables.qpath_def(qpath, vec.id)),
diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
index ce5065a916b..db595b07969 100644
--- a/clippy_lints/src/utils/mod.rs
+++ b/clippy_lints/src/utils/mod.rs
@@ -112,12 +112,12 @@ pub fn in_constant(cx: &LateContext, id: NodeId) -> bool {
 
 /// Returns true if this `expn_info` was expanded by any macro.
 pub fn in_macro(span: Span) -> bool {
-    span.ctxt.outer().expn_info().map(|info| {
+    span.ctxt.outer().expn_info().map_or(false, |info| {
         match info.callee.format {// don't treat range expressions desugared to structs as "in_macro"
             ExpnFormat::CompilerDesugaring(name) => name != "...",
             _ => true,
         }
-    }).unwrap_or(false)
+    })
 }
 
 /// Returns true if the macro that expanded the crate was outside of the current crate or was a
@@ -138,7 +138,7 @@ pub fn in_external_macro<'a, T: LintContext<'a>>(cx: &T, span: Span) -> bool {
         })
     }
 
-    span.ctxt.outer().expn_info().map(|info| in_macro_ext(cx, &info)).unwrap_or(false)
+    span.ctxt.outer().expn_info().map_or(false, |info| in_macro_ext(cx, &info))
 }
 
 /// Check if a `DefId`'s path matches the given absolute type path usage.