use matches!() macro for simple if let conditions

Author: matthiaskrgr

compiler/rustc_ast/src/ast.rs

@@ -1931,7 +1931,7 @@ pub enum TyKind {
 
 impl TyKind {
     pub fn is_implicit_self(&self) -> bool {
-        if let TyKind::ImplicitSelf = *self { true } else { false }
+        matches!(self, TyKind::ImplicitSelf)
     }
 
     pub fn is_unit(&self) -> bool {
@@ -2227,7 +2227,7 @@ pub enum Async {
 
 impl Async {
     pub fn is_async(self) -> bool {
-        if let Async::Yes { .. } = self { true } else { false }
+        matches!(self, Async::Yes { .. })
     }
 
     /// In this case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
@@ -2508,7 +2508,7 @@ pub enum VisibilityKind {
 
 impl VisibilityKind {
     pub fn is_pub(&self) -> bool {
-        if let VisibilityKind::Public = *self { true } else { false }
+        matches!(self, VisibilityKind::Public)
     }
 }
 

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -868,10 +868,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                     .emit();
                 }
 
-                if !bounds
-                    .iter()
-                    .any(|b| if let GenericBound::Trait(..) = *b { true } else { false })
-                {
+                if !bounds.iter().any(|b| matches!(b, GenericBound::Trait(..))) {
                     self.err_handler().span_err(ty.span, "at least one trait must be specified");
                 }
 

compiler/rustc_attr/src/builtin.rs

@@ -160,10 +160,10 @@ pub enum StabilityLevel {
 
 impl StabilityLevel {
     pub fn is_unstable(&self) -> bool {
-        if let StabilityLevel::Unstable { .. } = *self { true } else { false }
+        matches!(self, StabilityLevel::Unstable { .. })
     }
     pub fn is_stable(&self) -> bool {
-        if let StabilityLevel::Stable { .. } = *self { true } else { false }
+        matches!(self, StabilityLevel::Stable { .. })
     }
 }
 

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -1529,7 +1529,7 @@ impl<'a> TraitDef<'a> {
             }
         }
 
-        let is_tuple = if let ast::VariantData::Tuple(..) = struct_def { true } else { false };
+        let is_tuple = matches!(struct_def, ast::VariantData::Tuple(..));
         match (just_spans.is_empty(), named_idents.is_empty()) {
             (false, false) => cx.span_bug(
                 self.span,

compiler/rustc_errors/src/snippet.rs

@@ -118,17 +118,15 @@ pub struct Annotation {
 impl Annotation {
     /// Whether this annotation is a vertical line placeholder.
     pub fn is_line(&self) -> bool {
-        if let AnnotationType::MultilineLine(_) = self.annotation_type { true } else { false }
+        matches!(self.annotation_type, AnnotationType::MultilineLine(_))
     }
 
     pub fn is_multiline(&self) -> bool {
-        match self.annotation_type {
+        matches!(self.annotation_type,
             AnnotationType::Multiline(_)
             | AnnotationType::MultilineStart(_)
             | AnnotationType::MultilineLine(_)
-            | AnnotationType::MultilineEnd(_) => true,
-            _ => false,
-        }
+            | AnnotationType::MultilineEnd(_))
     }
 
     pub fn len(&self) -> usize {

compiler/rustc_lint/src/builtin.rs

@@ -1985,9 +1985,9 @@ impl ExplicitOutlivesRequirements {
             .filter_map(|(i, bound)| {
                 if let hir::GenericBound::Outlives(lifetime) = bound {
                     let is_inferred = match tcx.named_region(lifetime.hir_id) {
-                        Some(Region::Static) if infer_static => inferred_outlives
-                            .iter()
-                            .any(|r| if let ty::ReStatic = r { true } else { false }),
+                        Some(Region::Static) if infer_static => {
+                            inferred_outlives.iter().any(|r| matches!(r, ty::ReStatic))
+                        }
                         Some(Region::EarlyBound(index, ..)) => inferred_outlives.iter().any(|r| {
                             if let ty::ReEarlyBound(ebr) = r { ebr.index == index } else { false }
                         }),
@@ -2079,9 +2079,10 @@ impl<'tcx> LateLintPass<'tcx> for ExplicitOutlivesRequirements {
             let mut lint_spans = Vec::new();
 
             for param in hir_generics.params {
-                let has_lifetime_bounds = param.bounds.iter().any(|bound| {
-                    if let hir::GenericBound::Outlives(_) = bound { true } else { false }
-                });
+                let has_lifetime_bounds = param
+                    .bounds
+                    .iter()
+                    .any(|bound| matches!(bound, hir::GenericBound::Outlives(_)));
                 if !has_lifetime_bounds {
                     continue;
                 }

compiler/rustc_middle/src/middle/cstore.rs

@@ -69,7 +69,7 @@ pub enum LibSource {
 
 impl LibSource {
     pub fn is_some(&self) -> bool {
-        if let LibSource::Some(_) = *self { true } else { false }
+        matches!(self, LibSource::Some(_))
     }
 
     pub fn option(&self) -> Option<PathBuf> {

compiler/rustc_mir/src/borrow_check/diagnostics/outlives_suggestion.rs

@@ -115,9 +115,10 @@ impl OutlivesSuggestionBuilder {
             //    should just replace 'a with 'static.
             // 3) Suggest unifying 'a with 'b if we have both 'a: 'b and 'b: 'a
 
-            if outlived.iter().any(|(_, outlived_name)| {
-                if let RegionNameSource::Static = outlived_name.source { true } else { false }
-            }) {
+            if outlived
+                .iter()
+                .any(|(_, outlived_name)| matches!(outlived_name.source, RegionNameSource::Static))
+            {
                 suggested.push(SuggestedConstraint::Static(fr_name));
             } else {
                 // We want to isolate out all lifetimes that should be unified and print out

compiler/rustc_mir/src/transform/promote_consts.rs

@@ -92,7 +92,7 @@ pub enum TempState {
 impl TempState {
     pub fn is_promotable(&self) -> bool {
         debug!("is_promotable: self={:?}", self);
-        if let TempState::Defined { .. } = *self { true } else { false }
+        matches!(self, TempState::Defined { .. } )
     }
 }
 

compiler/rustc_mir/src/transform/simplify.rs

@@ -281,8 +281,7 @@ impl<'a, 'tcx> CfgSimplifier<'a, 'tcx> {
 
     fn strip_nops(&mut self) {
         for blk in self.basic_blocks.iter_mut() {
-            blk.statements
-                .retain(|stmt| if let StatementKind::Nop = stmt.kind { false } else { true })
+            blk.statements.retain(|stmt| !matches!(stmt.kind, StatementKind::Nop))
         }
     }
 }