remove redundant closures (clippy::redundant_closure)

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs

@@ -292,7 +292,7 @@ fn add_unreachable_coverage<'tcx>(
         if let Some(non_codegenned_file_name) = tcx.covered_file_name(non_codegenned_def_id) {
             let def_ids = unreachable_def_ids_by_file
                 .entry(*non_codegenned_file_name)
-                .or_insert_with(|| Vec::new());
+                .or_insert_with(Vec::new);
             def_ids.push(non_codegenned_def_id);
         }
     }

compiler/rustc_codegen_ssa/src/coverageinfo/map.rs

@@ -170,30 +170,30 @@ impl<'tcx> FunctionCoverage<'tcx> {
         // `expression_index`s lower than the referencing `Expression`. Therefore, it is
         // reasonable to look up the new index of an expression operand while the `new_indexes`
         // vector is only complete up to the current `ExpressionIndex`.
-        let id_to_counter =
-            |new_indexes: &IndexVec<InjectedExpressionIndex, Option<MappedExpressionIndex>>,
-             id: ExpressionOperandId| {
-                if id == ExpressionOperandId::ZERO {
-                    Some(Counter::zero())
-                } else if id.index() < self.counters.len() {
-                    // Note: Some codegen-injected Counters may be only referenced by `Expression`s,
-                    // and may not have their own `CodeRegion`s,
-                    let index = CounterValueReference::from(id.index());
-                    Some(Counter::counter_value_reference(index))
-                } else {
-                    let index = self.expression_index(u32::from(id));
-                    self.expressions
-                        .get(index)
-                        .expect("expression id is out of range")
-                        .as_ref()
-                        // If an expression was optimized out, assume it would have produced a count
-                        // of zero. This ensures that expressions dependent on optimized-out
-                        // expressions are still valid.
-                        .map_or(Some(Counter::zero()), |_| {
-                            new_indexes[index].map(|new_index| Counter::expression(new_index))
-                        })
-                }
-            };
+        let id_to_counter = |new_indexes: &IndexVec<
+            InjectedExpressionIndex,
+            Option<MappedExpressionIndex>,
+        >,
+                             id: ExpressionOperandId| {
+            if id == ExpressionOperandId::ZERO {
+                Some(Counter::zero())
+            } else if id.index() < self.counters.len() {
+                // Note: Some codegen-injected Counters may be only referenced by `Expression`s,
+                // and may not have their own `CodeRegion`s,
+                let index = CounterValueReference::from(id.index());
+                Some(Counter::counter_value_reference(index))
+            } else {
+                let index = self.expression_index(u32::from(id));
+                self.expressions
+                    .get(index)
+                    .expect("expression id is out of range")
+                    .as_ref()
+                    // If an expression was optimized out, assume it would have produced a count
+                    // of zero. This ensures that expressions dependent on optimized-out
+                    // expressions are still valid.
+                    .map_or(Some(Counter::zero()), |_| new_indexes[index].map(Counter::expression))
+            }
+        };
 
         for (original_index, expression) in
             self.expressions.iter_enumerated().filter_map(|(original_index, entry)| {

compiler/rustc_data_structures/src/fingerprint.rs

@@ -198,7 +198,7 @@ impl<E: rustc_serialize::Encoder> Encodable<E> for PackedFingerprint {
 impl<D: rustc_serialize::Decoder> Decodable<D> for PackedFingerprint {
     #[inline]
     fn decode(d: &mut D) -> Result<Self, D::Error> {
-        Fingerprint::decode(d).map(|f| PackedFingerprint(f))
+        Fingerprint::decode(d).map(PackedFingerprint)
     }
 }
 

compiler/rustc_expand/src/tests.rs

@@ -92,7 +92,7 @@ crate fn matches_codepattern(a: &str, b: &str) -> bool {
 
 /// Advances the given peekable `Iterator` until it reaches a non-whitespace character.
 fn scan_for_non_ws_or_end<I: Iterator<Item = char>>(iter: &mut Peekable<I>) {
-    while iter.peek().copied().map(|c| rustc_lexer::is_whitespace(c)) == Some(true) {
+    while iter.peek().copied().map(rustc_lexer::is_whitespace) == Some(true) {
         iter.next();
     }
 }

compiler/rustc_graphviz/src/tests.rs

@@ -55,7 +55,7 @@ impl NodeLabels<&'static str> {
     fn to_opt_strs(self) -> Vec<Option<&'static str>> {
         match self {
             UnlabelledNodes(len) => vec![None; len],
-            AllNodesLabelled(lbls) => lbls.into_iter().map(|l| Some(l)).collect(),
+            AllNodesLabelled(lbls) => lbls.into_iter().map(Some).collect(),
             SomeNodesLabelled(lbls) => lbls.into_iter().collect(),
         }
     }

compiler/rustc_middle/src/ty/mod.rs

@@ -1429,22 +1429,21 @@ impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitPredicate<'tcx>> {
 
 impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        self.map_bound(|value| PredicateAtom::RegionOutlives(value))
+        self.map_bound(PredicateAtom::RegionOutlives)
             .potentially_quantified(tcx, PredicateKind::ForAll)
     }
 }
 
 impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        self.map_bound(|value| PredicateAtom::TypeOutlives(value))
+        self.map_bound(PredicateAtom::TypeOutlives)
             .potentially_quantified(tcx, PredicateKind::ForAll)
     }
 }
 
 impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
-        self.map_bound(|value| PredicateAtom::Projection(value))
-            .potentially_quantified(tcx, PredicateKind::ForAll)
+        self.map_bound(PredicateAtom::Projection).potentially_quantified(tcx, PredicateKind::ForAll)
     }
 }
 

compiler/rustc_mir/src/transform/coverage/debug.rs

@@ -130,7 +130,7 @@ const RUSTC_COVERAGE_DEBUG_OPTIONS: &str = "RUSTC_COVERAGE_DEBUG_OPTIONS";
 pub(super) fn debug_options<'a>() -> &'a DebugOptions {
     static DEBUG_OPTIONS: SyncOnceCell<DebugOptions> = SyncOnceCell::new();
 
-    &DEBUG_OPTIONS.get_or_init(|| DebugOptions::from_env())
+    &DEBUG_OPTIONS.get_or_init(DebugOptions::from_env)
 }
 
 /// Parses and maintains coverage-specific debug options captured from the environment variable
@@ -430,7 +430,7 @@ impl GraphvizData {
         {
             bcb_to_coverage_spans_with_counters
                 .entry(bcb)
-                .or_insert_with(|| Vec::new())
+                .or_insert_with(Vec::new)
                 .push((coverage_span.clone(), counter_kind.clone()));
         }
     }
@@ -456,7 +456,7 @@ impl GraphvizData {
         if let Some(bcb_to_dependency_counters) = self.some_bcb_to_dependency_counters.as_mut() {
             bcb_to_dependency_counters
                 .entry(bcb)
-                .or_insert_with(|| Vec::new())
+                .or_insert_with(Vec::new)
                 .push(counter_kind.clone());
         }
     }
@@ -527,8 +527,8 @@ impl UsedExpressions {
     pub fn add_expression_operands(&mut self, expression: &CoverageKind) {
         if let Some(used_expression_operands) = self.some_used_expression_operands.as_mut() {
             if let CoverageKind::Expression { id, lhs, rhs, .. } = *expression {
-                used_expression_operands.entry(lhs).or_insert_with(|| Vec::new()).push(id);
-                used_expression_operands.entry(rhs).or_insert_with(|| Vec::new()).push(id);
+                used_expression_operands.entry(lhs).or_insert_with(Vec::new).push(id);
+                used_expression_operands.entry(rhs).or_insert_with(Vec::new).push(id);
             }
         }
     }

compiler/rustc_mir/src/transform/coverage/graph.rs

@@ -394,7 +394,7 @@ impl BasicCoverageBlockData {
         let operand = counter_kind.as_operand_id();
         if let Some(replaced) = self
             .edge_from_bcbs
-            .get_or_insert_with(|| FxHashMap::default())
+            .get_or_insert_with(FxHashMap::default)
             .insert(from_bcb, counter_kind)
         {
             Error::from_string(format!(

compiler/rustc_span/src/analyze_source_file/tests.rs

@@ -12,7 +12,7 @@ macro_rules! test {
             let (lines, multi_byte_chars, non_narrow_chars) =
                 analyze_source_file($text, BytePos($source_file_start_pos));
 
-            let expected_lines: Vec<BytePos> = $lines.into_iter().map(|pos| BytePos(pos)).collect();
+            let expected_lines: Vec<BytePos> = $lines.into_iter().map(BytePos).collect();
 
             assert_eq!(lines, expected_lines);
 

compiler/rustc_span/src/lev_distance/tests.rs

@@ -4,7 +4,7 @@ use super::*;
 fn test_lev_distance() {
     use std::char::{from_u32, MAX};
     // Test bytelength agnosticity
-    for c in (0..MAX as u32).filter_map(|i| from_u32(i)).map(|i| i.to_string()) {
+    for c in (0..MAX as u32).filter_map(from_u32).map(|i| i.to_string()) {
         assert_eq!(lev_distance(&c[..], &c[..]), 0);
     }
 

compiler/rustc_typeck/src/astconv/mod.rs

@@ -1256,17 +1256,15 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             })
         });
 
-        let regular_trait_predicates = existential_trait_refs.map(|trait_ref| {
-            trait_ref.map_bound(|trait_ref| ty::ExistentialPredicate::Trait(trait_ref))
-        });
+        let regular_trait_predicates = existential_trait_refs
+            .map(|trait_ref| trait_ref.map_bound(ty::ExistentialPredicate::Trait));
         let auto_trait_predicates = auto_traits.into_iter().map(|trait_ref| {
             ty::Binder::dummy(ty::ExistentialPredicate::AutoTrait(trait_ref.trait_ref().def_id()))
         });
         let mut v = regular_trait_predicates
             .chain(auto_trait_predicates)
             .chain(
-                existential_projections
-                    .map(|x| x.map_bound(|x| ty::ExistentialPredicate::Projection(x))),
+                existential_projections.map(|x| x.map_bound(ty::ExistentialPredicate::Projection)),
             )
             .collect::<SmallVec<[_; 8]>>();
         v.sort_by(|a, b| a.skip_binder().stable_cmp(tcx, &b.skip_binder()));