Auto merge of #93455 - asquared31415:vec-zero-opts, r=thomcc

[rust.git] / compiler / rustc_mir_build / src / thir / pattern / deconstruct_pat.rs

diff --git a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
index 8d6f8efb6003f9fd7745b02e331859f14cc3ab77..5105f059f9b64797317ac251dc630389a8a1ceb8 100644 (file)
--- a/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs
@@ -71,9 +71,9 @@
 /// Recursively expand this pattern into its subpatterns. Only useful for or-patterns.
 fn expand_or_pat<'p, 'tcx>(pat: &'p Pat<'tcx>) -> Vec<&'p Pat<'tcx>> {
     fn expand<'p, 'tcx>(pat: &'p Pat<'tcx>, vec: &mut Vec<&'p Pat<'tcx>>) {
-        if let PatKind::Or { pats } = pat.kind.as_ref() {
-            for pat in pats {
-                expand(pat, vec);
+        if let PatKind::Or { pats } = &pat.kind {
+            for pat in pats.iter() {
+                expand(&pat, vec);
             }
         } else {
             vec.push(pat)
@@ -252,10 +252,14 @@ fn to_pat<'tcx>(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Pat<'tcx> {
         let kind = if lo == hi {
             PatKind::Constant { value: lo_const }
         } else {
-            PatKind::Range(PatRange { lo: lo_const, hi: hi_const, end: RangeEnd::Included })
+            PatKind::Range(Box::new(PatRange {
+                lo: lo_const,
+                hi: hi_const,
+                end: RangeEnd::Included,
+            }))
         };
 
-        Pat { ty, span: DUMMY_SP, kind: Box::new(kind) }
+        Pat { ty, span: DUMMY_SP, kind }
     }
 
     /// Lint on likely incorrect range patterns (#63987)
@@ -1297,7 +1301,7 @@ pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
         let mkpat = |pat| DeconstructedPat::from_pat(cx, pat);
         let ctor;
         let fields;
-        match pat.kind.as_ref() {
+        match &pat.kind {
             PatKind::AscribeUserType { subpattern, .. } => return mkpat(subpattern),
             PatKind::Binding { subpattern: Some(subpat), .. } => return mkpat(subpat),
             PatKind::Binding { subpattern: None, .. } | PatKind::Wild => {
@@ -1342,9 +1346,9 @@ pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
                         fields = Fields::singleton(cx, pat);
                     }
                     ty::Adt(adt, _) => {
-                        ctor = match pat.kind.as_ref() {
+                        ctor = match pat.kind {
                             PatKind::Leaf { .. } => Single,
-                            PatKind::Variant { variant_index, .. } => Variant(*variant_index),
+                            PatKind::Variant { variant_index, .. } => Variant(variant_index),
                             _ => bug!(),
                         };
                         let variant = &adt.variant(ctor.variant_index_for_adt(*adt));
@@ -1402,7 +1406,7 @@ pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
                     }
                 }
             }
-            &PatKind::Range(PatRange { lo, hi, end }) => {
+            &PatKind::Range(box PatRange { lo, hi, end }) => {
                 let ty = lo.ty();
                 ctor = if let Some(int_range) = IntRange::from_range(
                     cx.tcx,
@@ -1429,7 +1433,8 @@ pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
                     FixedLen(prefix.len() + suffix.len())
                 };
                 ctor = Slice(Slice::new(array_len, kind));
-                fields = Fields::from_iter(cx, prefix.iter().chain(suffix).map(mkpat));
+                fields =
+                    Fields::from_iter(cx, prefix.iter().chain(suffix.iter()).map(|p| mkpat(&*p)));
             }
             PatKind::Or { .. } => {
                 ctor = Or;
@@ -1442,15 +1447,15 @@ pub(crate) fn from_pat(cx: &MatchCheckCtxt<'p, 'tcx>, pat: &Pat<'tcx>) -> Self {
 
     pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> {
         let is_wildcard = |pat: &Pat<'_>| {
-            matches!(*pat.kind, PatKind::Binding { subpattern: None, .. } | PatKind::Wild)
+            matches!(pat.kind, PatKind::Binding { subpattern: None, .. } | PatKind::Wild)
         };
-        let mut subpatterns = self.iter_fields().map(|p| p.to_pat(cx));
-        let pat = match &self.ctor {
+        let mut subpatterns = self.iter_fields().map(|p| Box::new(p.to_pat(cx)));
+        let kind = match &self.ctor {
             Single | Variant(_) => match self.ty.kind() {
                 ty::Tuple(..) => PatKind::Leaf {
                     subpatterns: subpatterns
                         .enumerate()
-                        .map(|(i, p)| FieldPat { field: Field::new(i), pattern: p })
+                        .map(|(i, pattern)| FieldPat { field: Field::new(i), pattern })
                         .collect(),
                 },
                 ty::Adt(adt_def, _) if adt_def.is_box() => {
@@ -1485,7 +1490,7 @@ pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> {
                     FixedLen(_) => PatKind::Slice {
                         prefix: subpatterns.collect(),
                         slice: None,
-                        suffix: vec![],
+                        suffix: Box::new([]),
                     },
                     VarLen(prefix, _) => {
                         let mut subpatterns = subpatterns.peekable();
@@ -1504,14 +1509,18 @@ pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> {
                                 subpatterns.next();
                             }
                         }
-                        let suffix: Vec<_> = subpatterns.collect();
+                        let suffix: Box<[_]> = subpatterns.collect();
                         let wild = Pat::wildcard_from_ty(self.ty);
-                        PatKind::Slice { prefix, slice: Some(wild), suffix }
+                        PatKind::Slice {
+                            prefix: prefix.into_boxed_slice(),
+                            slice: Some(Box::new(wild)),
+                            suffix,
+                        }
                     }
                 }
             }
             &Str(value) => PatKind::Constant { value },
-            &FloatRange(lo, hi, end) => PatKind::Range(PatRange { lo, hi, end }),
+            &FloatRange(lo, hi, end) => PatKind::Range(Box::new(PatRange { lo, hi, end })),
             IntRange(range) => return range.to_pat(cx.tcx, self.ty),
             Wildcard | NonExhaustive => PatKind::Wild,
             Missing { .. } => bug!(
@@ -1523,7 +1532,7 @@ pub(crate) fn to_pat(&self, cx: &MatchCheckCtxt<'p, 'tcx>) -> Pat<'tcx> {
             }
         };
 
-        Pat { ty: self.ty, span: DUMMY_SP, kind: Box::new(pat) }
+        Pat { ty: self.ty, span: DUMMY_SP, kind }
     }
 
     pub(super) fn is_or_pat(&self) -> bool {