Remove index from BrAnon

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1342,9 +1342,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 
                     let region_ctxt_fn = || {
                         let reg_info = match br.kind {
-                            ty::BoundRegionKind::BrAnon(_, Some(span)) => {
+                            ty::BoundRegionKind::BrAnon(Some(span)) => BoundRegionInfo::Span(span),
-                                BoundRegionInfo::Span(span)
-                            }
                             ty::BoundRegionKind::BrAnon(..) => {
                                 BoundRegionInfo::Name(Symbol::intern("anon"))
                             }

compiler/rustc_borrowck/src/type_check/relate_tys.rs

@@ -124,7 +124,7 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for NllTypeRelatingDelegate<'_, '_, 'tcx>
             .placeholder_region(self.type_checker.infcx, placeholder);
 
         let reg_info = match placeholder.bound.kind {
-            ty::BoundRegionKind::BrAnon(_, Some(span)) => BoundRegionInfo::Span(span),
+            ty::BoundRegionKind::BrAnon(Some(span)) => BoundRegionInfo::Span(span),
             ty::BoundRegionKind::BrAnon(..) => BoundRegionInfo::Name(Symbol::intern("anon")),
             ty::BoundRegionKind::BrNamed(_, name) => BoundRegionInfo::Name(name),
             ty::BoundRegionKind::BrEnv => BoundRegionInfo::Name(Symbol::intern("env")),

compiler/rustc_hir_analysis/src/check/intrinsic.rs

@@ -139,14 +139,14 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
     let name_str = intrinsic_name.as_str();
 
     let bound_vars = tcx.mk_bound_variable_kinds(&[
-        ty::BoundVariableKind::Region(ty::BrAnon(0, None)),
+        ty::BoundVariableKind::Region(ty::BrAnon(None)),
         ty::BoundVariableKind::Region(ty::BrEnv),
     ]);
     let mk_va_list_ty = |mutbl| {
         tcx.lang_items().va_list().map(|did| {
             let region = tcx.mk_re_late_bound(
                 ty::INNERMOST,
-                ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0, None) },
+                ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(None) },
             );
             let env_region = tcx.mk_re_late_bound(
                 ty::INNERMOST,
@@ -387,8 +387,7 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
                 );
                 let discriminant_def_id = assoc_items[0];
 
-                let br =
+                let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(None) };
-                    ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0, None) };
                 (
                     1,
                     vec![tcx.mk_imm_ref(tcx.mk_re_late_bound(ty::INNERMOST, br), param(0))],
@@ -440,8 +439,7 @@ pub fn check_intrinsic_type(tcx: TyCtxt<'_>, it: &hir::ForeignItem<'_>) {
             sym::nontemporal_store => (1, vec![tcx.mk_mut_ptr(param(0)), param(0)], tcx.mk_unit()),
 
             sym::raw_eq => {
-                let br =
+                let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(None) };
-                    ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind: ty::BrAnon(0, None) };
                 let param_ty = tcx.mk_imm_ref(tcx.mk_re_late_bound(ty::INNERMOST, br), param(0));
                 (1, vec![param_ty; 2], tcx.types.bool)
             }

compiler/rustc_hir_typeck/src/generator_interior/mod.rs

@@ -240,7 +240,7 @@ pub fn resolve_interior<'a, 'tcx>(
 
             let mut counter = 0;
             let mut mk_bound_region = |span| {
-                let kind = ty::BrAnon(counter, span);
+                let kind = ty::BrAnon(span);
                 let var = ty::BoundVar::from_u32(counter);
                 counter += 1;
                 ty::BoundRegion { var, kind }
@@ -263,7 +263,7 @@ pub fn resolve_interior<'a, 'tcx>(
                     }
                     ty::ReLateBound(_, ty::BoundRegion { kind, .. })
                     | ty::ReFree(ty::FreeRegion { bound_region: kind, .. }) => match kind {
-                        ty::BoundRegionKind::BrAnon(_, span) => mk_bound_region(span),
+                        ty::BoundRegionKind::BrAnon(span) => mk_bound_region(span),
                         ty::BoundRegionKind::BrNamed(def_id, _) => {
                             mk_bound_region(Some(fcx.tcx.def_span(def_id)))
                         }
@@ -294,7 +294,7 @@ pub fn resolve_interior<'a, 'tcx>(
             FnMutDelegate {
                 regions: &mut |br| {
                     let kind = match br.kind {
-                        ty::BrAnon(_, span) => ty::BrAnon(counter, span),
+                        ty::BrAnon(span) => ty::BrAnon(span),
                         _ => br.kind,
                     };
                     let var = ty::BoundVar::from_usize(bound_vars.len());

compiler/rustc_infer/src/errors/note_and_explain.rs

@@ -90,7 +90,7 @@ impl<'a> DescriptionCtx<'a> {
                             };
                             me.span = Some(sp);
                         }
-                        ty::BrAnon(_, span) => {
+                        ty::BrAnon(span) => {
                             me.kind = "defined_here";
                             me.span = match span {
                                 Some(_) => span,

compiler/rustc_infer/src/infer/canonical/canonicalizer.rs

@@ -772,7 +772,7 @@ impl<'cx, 'tcx> Canonicalizer<'cx, 'tcx> {
         r: ty::Region<'tcx>,
     ) -> ty::Region<'tcx> {
         let var = self.canonical_var(info, r.into());
-        let br = ty::BoundRegion { var, kind: ty::BrAnon(var.as_u32(), None) };
+        let br = ty::BoundRegion { var, kind: ty::BrAnon(None) };
         self.interner().mk_re_late_bound(self.binder_index, br)
     }
 

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -174,11 +174,11 @@ fn msg_span_from_named_region<'tcx>(
             ..
         }) => (format!("the lifetime `{name}` as defined here"), Some(tcx.def_span(def_id))),
         ty::RePlaceholder(ty::PlaceholderRegion {
-            bound: ty::BoundRegion { kind: ty::BoundRegionKind::BrAnon(_, Some(span)), .. },
+            bound: ty::BoundRegion { kind: ty::BoundRegionKind::BrAnon(Some(span)), .. },
             ..
         }) => (format!("the anonymous lifetime defined here"), Some(span)),
         ty::RePlaceholder(ty::PlaceholderRegion {
-            bound: ty::BoundRegion { kind: ty::BoundRegionKind::BrAnon(_, None), .. },
+            bound: ty::BoundRegion { kind: ty::BoundRegionKind::BrAnon(None), .. },
             ..
         }) => (format!("an anonymous lifetime"), None),
         _ => bug!("{:?}", region),
@@ -226,7 +226,7 @@ fn msg_span_from_early_bound_and_free_regions<'tcx>(
                         };
                         (text, sp)
                     }
-                    ty::BrAnon(_, span) => (
+                    ty::BrAnon(span) => (
                         "the anonymous lifetime as defined here".to_string(),
                         match span {
                             Some(span) => span,

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_relation.rs

@@ -36,14 +36,14 @@ impl<'tcx> NiceRegionError<'_, 'tcx> {
                     ty::BrNamed(def_id, symbol) => {
                         (Some(self.tcx().def_span(def_id)), Some(symbol))
                     }
-                    ty::BrAnon(_, span) => (*span, None),
+                    ty::BrAnon(span) => (*span, None),
                     ty::BrEnv => (None, None),
                 };
                 let (sup_span, sup_symbol) = match sup_name {
                     ty::BrNamed(def_id, symbol) => {
                         (Some(self.tcx().def_span(def_id)), Some(symbol))
                     }
-                    ty::BrAnon(_, span) => (*span, None),
+                    ty::BrAnon(span) => (*span, None),
                     ty::BrEnv => (None, None),
                 };
                 let diag = match (sub_span, sup_span, sub_symbol, sup_symbol) {

compiler/rustc_middle/src/infer/canonical.rs

@@ -411,7 +411,7 @@ impl<'tcx> CanonicalVarValues<'tcx> {
                         CanonicalVarKind::Region(_) | CanonicalVarKind::PlaceholderRegion(_) => {
                             let br = ty::BoundRegion {
                                 var: ty::BoundVar::from_usize(i),
-                                kind: ty::BrAnon(i as u32, None),
+                                kind: ty::BrAnon(None),
                             };
                             tcx.mk_re_late_bound(ty::INNERMOST, br).into()
                         }

compiler/rustc_middle/src/mir/query.rs

@@ -411,10 +411,8 @@ impl<'tcx> ClosureOutlivesSubjectTy<'tcx> {
     pub fn bind(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Self {
         let inner = tcx.fold_regions(ty, |r, depth| match r.kind() {
             ty::ReVar(vid) => {
-                let br = ty::BoundRegion {
+                let br =
-                    var: ty::BoundVar::new(vid.index()),
+                    ty::BoundRegion { var: ty::BoundVar::new(vid.index()), kind: ty::BrAnon(None) };
-                    kind: ty::BrAnon(vid.as_u32(), None),
-                };
                 tcx.mk_re_late_bound(depth, br)
             }
             _ => bug!("unexpected region in ClosureOutlivesSubjectTy: {r:?}"),

compiler/rustc_middle/src/ty/context.rs

@@ -311,7 +311,7 @@ pub struct CommonLifetimes<'tcx> {
     pub re_vars: Vec<Region<'tcx>>,
 
     /// Pre-interned values of the form:
-    /// `ReLateBound(DebruijnIndex(i), BoundRegion { var: v, kind: BrAnon(v, None) })`
+    /// `ReLateBound(DebruijnIndex(i), BoundRegion { var: v, kind: BrAnon(None) })`
     /// for small values of `i` and `v`.
     pub re_late_bounds: Vec<Vec<Region<'tcx>>>,
 }
@@ -386,10 +386,7 @@ impl<'tcx> CommonLifetimes<'tcx> {
                     .map(|v| {
                         mk(ty::ReLateBound(
                             ty::DebruijnIndex::from(i),
-                            ty::BoundRegion {
+                            ty::BoundRegion { var: ty::BoundVar::from(v), kind: ty::BrAnon(None) },
-                                var: ty::BoundVar::from(v),
-                                kind: ty::BrAnon(v, None),
-                            },
                         ))
                     })
                     .collect()
@@ -2075,10 +2072,9 @@ impl<'tcx> TyCtxt<'tcx> {
         bound_region: ty::BoundRegion,
     ) -> Region<'tcx> {
         // Use a pre-interned one when possible.
-        if let ty::BoundRegion { var, kind: ty::BrAnon(v, None) } = bound_region
+        if let ty::BoundRegion { var, kind: ty::BrAnon(None) } = bound_region
-            && var.as_u32() == v
             && let Some(inner) = self.lifetimes.re_late_bounds.get(debruijn.as_usize())
-            && let Some(re) = inner.get(v as usize).copied()
+            && let Some(re) = inner.get(var.as_usize()).copied()
         {
             re
         } else {

compiler/rustc_middle/src/ty/fold.rs

@@ -379,9 +379,7 @@ impl<'tcx> TyCtxt<'tcx> {
                 let index = entry.index();
                 let var = ty::BoundVar::from_usize(index);
                 let kind = entry
-                    .or_insert_with(|| {
+                    .or_insert_with(|| ty::BoundVariableKind::Region(ty::BrAnon(None)))
-                        ty::BoundVariableKind::Region(ty::BrAnon(index as u32, None))
-                    })
                     .expect_region();
                 let br = ty::BoundRegion { var, kind };
                 self.tcx.mk_re_late_bound(ty::INNERMOST, br)

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -68,7 +68,7 @@ impl<'tcx> fmt::Debug for ty::adjustment::Adjustment<'tcx> {
 impl fmt::Debug for ty::BoundRegionKind {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
-            ty::BrAnon(n, span) => write!(f, "BrAnon({n:?}, {span:?})"),
+            ty::BrAnon(span) => write!(f, "BrAnon({span:?})"),
             ty::BrNamed(did, name) => {
                 if did.is_crate_root() {
                     write!(f, "BrNamed({})", name)

compiler/rustc_middle/src/ty/sty.rs

@@ -60,7 +60,7 @@ pub struct FreeRegion {
 #[derive(HashStable)]
 pub enum BoundRegionKind {
     /// An anonymous region parameter for a given fn (&T)
-    BrAnon(u32, Option<Span>),
+    BrAnon(Option<Span>),
 
     /// Named region parameters for functions (a in &'a T)
     ///

compiler/rustc_symbol_mangling/src/v0.rs

@@ -1,5 +1,5 @@
 use rustc_data_structures::base_n;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::intern::Interned;
 use rustc_hir as hir;
 use rustc_hir::def::CtorKind;
@@ -81,9 +81,9 @@ pub(super) fn mangle_typeid_for_trait_ref<'tcx>(
 struct BinderLevel {
     /// The range of distances from the root of what's
     /// being printed, to the lifetimes in a binder.
-    /// Specifically, a `BrAnon(i)` lifetime has depth
+    /// Specifically, a `BrAnon` lifetime has depth
-    /// `lifetime_depths.start + i`, going away from the
+    /// `lifetime_depths.start + index`, going away from the
-    /// the root and towards its use site, as `i` increases.
+    /// the root and towards its use site, as the var index increases.
     /// This is used to flatten rustc's pairing of `BrAnon`
     /// (intra-binder disambiguation) with a `DebruijnIndex`
     /// (binder addressing), to "true" de Bruijn indices,
@@ -208,24 +208,15 @@ impl<'tcx> SymbolMangler<'tcx> {
     where
         T: TypeVisitable<TyCtxt<'tcx>>,
     {
-        // FIXME(non-lifetime-binders): What to do here?
-        let regions = if value.has_late_bound_regions() {
-            self.tcx.collect_referenced_late_bound_regions(value)
-        } else {
-            FxHashSet::default()
-        };
-
         let mut lifetime_depths =
             self.binders.last().map(|b| b.lifetime_depths.end).map_or(0..0, |i| i..i);
 
-        let lifetimes = regions
+        // FIXME(non-lifetime-binders): What to do here?
-            .into_iter()
+        let lifetimes = value
-            .map(|br| match br {
+            .bound_vars()
-                ty::BrAnon(i, _) => i,
+            .iter()
-                _ => bug!("symbol_names: non-anonymized region `{:?}` in `{:?}`", br, value),
+            .filter(|var| matches!(var, ty::BoundVariableKind::Region(..)))
-            })
+            .count() as u32;
-            .max()
-            .map_or(0, |max| max + 1);
 
         self.push_opt_integer_62("G", lifetimes as u64);
         lifetime_depths.end += lifetimes;
@@ -338,9 +329,9 @@ impl<'tcx> Printer<'tcx> for &mut SymbolMangler<'tcx> {
 
             // Late-bound lifetimes use indices starting at 1,
             // see `BinderLevel` for more details.
-            ty::ReLateBound(debruijn, ty::BoundRegion { kind: ty::BrAnon(i, _), .. }) => {
+            ty::ReLateBound(debruijn, ty::BoundRegion { var, kind: ty::BrAnon(_) }) => {
                 let binder = &self.binders[self.binders.len() - 1 - debruijn.index()];
-                let depth = binder.lifetime_depths.start + i;
+                let depth = binder.lifetime_depths.start + var.as_u32();
 
                 1 + (self.binders.last().unwrap().lifetime_depths.end - 1 - depth)
             }

compiler/rustc_trait_selection/src/solve/canonicalize.rs

@@ -257,7 +257,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for Canonicalizer<'_, 'tcx> {
             self.primitive_var_infos.push(CanonicalVarInfo { kind });
             var
         });
-        let br = ty::BoundRegion { var, kind: BrAnon(var.as_u32(), None) };
+        let br = ty::BoundRegion { var, kind: BrAnon(None) };
         self.interner().mk_re_late_bound(self.binder_index, br)
     }
 

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -3017,7 +3017,7 @@ fn bind_generator_hidden_types_above<'tcx>(
                     if let ty::ReErased = r.kind() {
                         let br = ty::BoundRegion {
                             var: ty::BoundVar::from_u32(counter),
-                            kind: ty::BrAnon(counter, None),
+                            kind: ty::BrAnon(None),
                         };
                         counter += 1;
                         r = tcx.mk_re_late_bound(current_depth, br);
@@ -3033,7 +3033,7 @@ fn bind_generator_hidden_types_above<'tcx>(
         debug_assert!(!hidden_types.has_erased_regions());
     }
     let bound_vars = tcx.mk_bound_variable_kinds_from_iter(bound_vars.iter().chain(
-        (num_bound_variables..counter).map(|i| ty::BoundVariableKind::Region(ty::BrAnon(i, None))),
+        (num_bound_variables..counter).map(|_| ty::BoundVariableKind::Region(ty::BrAnon(None))),
     ));
     ty::Binder::bind_with_vars(hidden_types, bound_vars)
 }

compiler/rustc_traits/src/chalk/db.rs

@@ -730,7 +730,7 @@ fn bound_vars_for_item(tcx: TyCtxt<'_>, def_id: DefId) -> SubstsRef<'_> {
         ty::GenericParamDefKind::Lifetime => {
             let br = ty::BoundRegion {
                 var: ty::BoundVar::from_usize(substs.len()),
-                kind: ty::BrAnon(substs.len() as u32, None),
+                kind: ty::BrAnon(None),
             };
             tcx.mk_re_late_bound(ty::INNERMOST, br).into()
         }

compiler/rustc_traits/src/chalk/lowering.rs

@@ -533,7 +533,7 @@ impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'t
                 ty::DebruijnIndex::from_u32(var.debruijn.depth()),
                 ty::BoundRegion {
                     var: ty::BoundVar::from_usize(var.index),
-                    kind: ty::BrAnon(var.index as u32, None),
+                    kind: ty::BrAnon(None),
                 },
             ),
             chalk_ir::LifetimeData::InferenceVar(_var) => unimplemented!(),
@@ -541,7 +541,7 @@ impl<'tcx> LowerInto<'tcx, Region<'tcx>> for &chalk_ir::Lifetime<RustInterner<'t
                 universe: ty::UniverseIndex::from_usize(p.ui.counter),
                 bound: ty::BoundRegion {
                     var: ty::BoundVar::from_usize(p.idx),
-                    kind: ty::BoundRegionKind::BrAnon(p.idx as u32, None),
+                    kind: ty::BoundRegionKind::BrAnon(None),
                 },
             }),
             chalk_ir::LifetimeData::Static => tcx.lifetimes.re_static,
@@ -976,7 +976,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for BoundVarsCollector<'tcx> {
                     }
                 }
 
-                ty::BoundRegionKind::BrAnon(var, _) => match self.parameters.entry(var) {
+                ty::BoundRegionKind::BrAnon(_) => match self.parameters.entry(br.var.as_u32()) {
                     Entry::Vacant(entry) => {
                         entry.insert(chalk_ir::VariableKind::Lifetime);
                     }
@@ -1036,8 +1036,8 @@ impl<'a, 'tcx> TypeFolder<TyCtxt<'tcx>> for NamedBoundVarSubstitutor<'a, 'tcx> {
         match *r {
             ty::ReLateBound(index, br) if index == self.binder_index => match br.kind {
                 ty::BrNamed(def_id, _name) => match self.named_parameters.get(&def_id) {
-                    Some(idx) => {
+                    Some(_) => {
-                        let new_br = ty::BoundRegion { var: br.var, kind: ty::BrAnon(*idx, None) };
+                        let new_br = ty::BoundRegion { var: br.var, kind: ty::BrAnon(None) };
                         return self.tcx.mk_re_late_bound(index, new_br);
                     }
                     None => panic!("Missing `BrNamed`."),
@@ -1127,7 +1127,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ParamsSubstitutor<'tcx> {
                 Some(idx) => {
                     let br = ty::BoundRegion {
                         var: ty::BoundVar::from_u32(*idx),
-                        kind: ty::BrAnon(*idx, None),
+                        kind: ty::BrAnon(None),
                     };
                     self.tcx.mk_re_late_bound(self.binder_index, br)
                 }
@@ -1135,7 +1135,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ParamsSubstitutor<'tcx> {
                     let idx = self.named_regions.len() as u32;
                     let br = ty::BoundRegion {
                         var: ty::BoundVar::from_u32(idx),
-                        kind: ty::BrAnon(idx, None),
+                        kind: ty::BrAnon(None),
                     };
                     self.named_regions.insert(_re.def_id, idx);
                     self.tcx.mk_re_late_bound(self.binder_index, br)
@@ -1213,8 +1213,9 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for PlaceholdersCollector {
     fn visit_region(&mut self, r: Region<'tcx>) -> ControlFlow<Self::BreakTy> {
         match *r {
             ty::RePlaceholder(p) if p.universe == self.universe_index => {
-                if let ty::BoundRegionKind::BrAnon(anon, _) = p.bound.kind {
+                if let ty::BoundRegionKind::BrAnon(_) = p.bound.kind {
-                    self.next_anon_region_placeholder = self.next_anon_region_placeholder.max(anon);
+                    self.next_anon_region_placeholder =
+                        self.next_anon_region_placeholder.max(p.bound.var.as_u32());
                 }
                 // FIXME: This doesn't seem to handle BrNamed at all?
             }

tests/ui/impl-trait/impl-fn-hrtb-bounds-2.stderr

@@ -6,7 +6,7 @@ LL | fn a() -> impl Fn(&u8) -> impl Debug {
 LL |     |x| x
    |     --- ^
    |     |
-   |     hidden type `&u8` captures the anonymous lifetime #1 defined here
+   |     hidden type `&u8` captures the anonymous lifetime as defined here
 
 error: aborting due to previous error
 

tests/ui/nll/closure-requirements/escape-argument-callee.stderr

@@ -6,7 +6,7 @@ LL |         let mut closure = expect_sig(|p, y| *p = y);
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) i32)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) i32)),
                (),
            ]
 

tests/ui/nll/closure-requirements/escape-argument.stderr

@@ -6,7 +6,7 @@ LL |         let mut closure = expect_sig(|p, y| *p = y);
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) i32)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) mut &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) i32)),
                (),
            ]
 

tests/ui/nll/closure-requirements/propagate-approximated-fail-no-postdom.stderr

@@ -6,7 +6,7 @@ LL |         |_outlives1, _outlives2, _outlives3, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) &'_#3r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#4r

tests/ui/nll/closure-requirements/propagate-approximated-ref.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None)), Region(BrAnon(3, None)), Region(BrAnon(4, None)), Region(BrAnon(5, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(4, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(5, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r

tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-comparing-against-free.stderr

@@ -6,7 +6,7 @@ LL |     foo(cell, |cell_a, cell_x| {
    |
    = note: defining type: case1::{closure#0} with closure substs [
                i32,
-               for<Region(BrAnon(0, None))> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>)),
+               for<Region(BrAnon(None))> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>)),
                (),
            ]
 
@@ -36,7 +36,7 @@ LL |     foo(cell, |cell_a, cell_x| {
    |
    = note: defining type: case2::{closure#0} with closure substs [
                i32,
-               for<Region(BrAnon(0, None))> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>)),
+               for<Region(BrAnon(None))> extern "rust-call" fn((std::cell::Cell<&'_#1r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: number of external vids: 2

tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-no-bound.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None)), Region(BrAnon(3, None)), Region(BrAnon(4, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(4, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#2r

tests/ui/nll/closure-requirements/propagate-approximated-shorter-to-static-wrong-bound.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None)), Region(BrAnon(3, None)), Region(BrAnon(4, None)), Region(BrAnon(5, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(4, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(5, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) std::cell::Cell<&'_#2r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r

tests/ui/nll/closure-requirements/propagate-approximated-val.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(cell_a, cell_b, |outlives1, outlives2, x, y| {
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r

tests/ui/nll/closure-requirements/propagate-despite-same-free-region.stderr

@@ -6,7 +6,7 @@ LL |         |_outlives1, _outlives2, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) &'_#2r u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) u32>, std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r

tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives, x, y| {
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None)), Region(BrAnon(3, None)), Region(BrAnon(4, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(4, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#2r

tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-wrong-bounds.stderr

@@ -6,7 +6,7 @@ LL |     establish_relationships(&cell_a, &cell_b, |_outlives1, _outlives2, x, y
    |
    = note: defining type: supply::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None)), Region(BrAnon(2, None)), Region(BrAnon(3, None)), Region(BrAnon(4, None)), Region(BrAnon(5, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(2, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(4, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(5, None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(3, None) }) u32>)),
+               for<Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) &'_#1r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 2, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) &'_#2r u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 4, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) u32>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 5, kind: BrAnon(None) }) std::cell::Cell<&ReLateBound(DebruijnIndex(0), BoundRegion { var: 3, kind: BrAnon(None) }) u32>)),
                (),
            ]
    = note: late-bound region is '_#3r

tests/ui/nll/closure-requirements/return-wrong-bound-region.stderr

@@ -6,7 +6,7 @@ LL |     expect_sig(|a, b| b); // ought to return `a`
    |
    = note: defining type: test::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) i32)) -> &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) i32,
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((&ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) i32, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) i32)) -> &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) i32,
                (),
            ]
 

tests/ui/nll/ty-outlives/ty-param-closure-approximate-lower-bound.stderr

@@ -6,7 +6,7 @@ LL |     twice(cell, value, |a, b| invoke(a, b));
    |
    = note: defining type: generic::<T>::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) T)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) T)),
                (),
            ]
    = note: number of external vids: 2
@@ -28,7 +28,7 @@ LL |     twice(cell, value, |a, b| invoke(a, b));
    |
    = note: defining type: generic_fail::<T>::{closure#0} with closure substs [
                i16,
-               for<Region(BrAnon(0, None)), Region(BrAnon(1, None))> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(0, None) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(1, None) }) T)),
+               for<Region(BrAnon(None)), Region(BrAnon(None))> extern "rust-call" fn((std::option::Option<std::cell::Cell<&'_#1r &ReLateBound(DebruijnIndex(0), BoundRegion { var: 0, kind: BrAnon(None) }) ()>>, &ReLateBound(DebruijnIndex(0), BoundRegion { var: 1, kind: BrAnon(None) }) T)),
                (),
            ]
    = note: late-bound region is '_#2r