Greatly simplify lifetime captures in edition 2024

Author: compiler-errors

compiler/rustc_abi/src/lib.rs

@@ -1345,7 +1345,7 @@ impl<FieldIdx: Idx> FieldsShape<FieldIdx> {
 
     /// Gets source indices of the fields by increasing offsets.
     #[inline]
-    pub fn index_by_increasing_offset(&self) -> impl ExactSizeIterator<Item = usize> + '_ {
+    pub fn index_by_increasing_offset(&self) -> impl ExactSizeIterator<Item = usize> {
         let mut inverse_small = [0u8; 64];
         let mut inverse_big = IndexVec::new();
         let use_small = self.count() <= inverse_small.len();

compiler/rustc_ast_lowering/src/lib.rs

@@ -45,7 +45,6 @@ use std::sync::Arc;
 
 use rustc_ast::node_id::NodeMap;
 use rustc_ast::{self as ast, *};
-use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::sorted_map::SortedMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
@@ -1821,11 +1820,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.new_named_lifetime_with_res(new_id, ident, res)
     }
 
-    fn lower_generic_params_mut<'s>(
-        &'s mut self,
-        params: &'s [GenericParam],
+    fn lower_generic_params_mut(
+        &mut self,
+        params: &[GenericParam],
         source: hir::GenericParamSource,
-    ) -> impl Iterator<Item = hir::GenericParam<'hir>> + Captures<'a> + Captures<'s> {
+    ) -> impl Iterator<Item = hir::GenericParam<'hir>> {
         params.iter().map(move |param| self.lower_generic_param(param, source))
     }
 
@@ -1986,11 +1985,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.arena.alloc_from_iter(self.lower_param_bounds_mut(bounds, itctx))
     }
 
-    fn lower_param_bounds_mut<'s>(
-        &'s mut self,
-        bounds: &'s [GenericBound],
+    fn lower_param_bounds_mut(
+        &mut self,
+        bounds: &[GenericBound],
         itctx: ImplTraitContext,
-    ) -> impl Iterator<Item = hir::GenericBound<'hir>> + Captures<'s> + Captures<'a> {
+    ) -> impl Iterator<Item = hir::GenericBound<'hir>> {
         bounds.iter().map(move |bound| self.lower_param_bound(bound, itctx))
     }
 

compiler/rustc_attr_parsing/src/attributes/allow_unstable.rs

@@ -4,25 +4,25 @@ use rustc_span::{Symbol, sym};
 
 use crate::session_diagnostics;
 
-pub fn allow_internal_unstable<'a>(
-    sess: &'a Session,
-    attrs: &'a [impl AttributeExt],
-) -> impl Iterator<Item = Symbol> + 'a {
+pub fn allow_internal_unstable(
+    sess: &Session,
+    attrs: &[impl AttributeExt],
+) -> impl Iterator<Item = Symbol> {
     allow_unstable(sess, attrs, sym::allow_internal_unstable)
 }
 
-pub fn rustc_allow_const_fn_unstable<'a>(
-    sess: &'a Session,
-    attrs: &'a [impl AttributeExt],
-) -> impl Iterator<Item = Symbol> + 'a {
+pub fn rustc_allow_const_fn_unstable(
+    sess: &Session,
+    attrs: &[impl AttributeExt],
+) -> impl Iterator<Item = Symbol> {
     allow_unstable(sess, attrs, sym::rustc_allow_const_fn_unstable)
 }
 
-fn allow_unstable<'a>(
-    sess: &'a Session,
-    attrs: &'a [impl AttributeExt],
+fn allow_unstable(
+    sess: &Session,
+    attrs: &[impl AttributeExt],
     symbol: Symbol,
-) -> impl Iterator<Item = Symbol> + 'a {
+) -> impl Iterator<Item = Symbol> {
     let attrs = filter_by_name(attrs, symbol);
     let list = attrs
         .filter_map(move |attr| {

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -8,7 +8,6 @@ use std::ops::ControlFlow;
 
 use either::Either;
 use hir::{ClosureKind, Path};
-use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::codes::*;
 use rustc_errors::{Applicability, Diag, MultiSpan, struct_span_code_err};
@@ -3530,10 +3529,10 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         location: Location,
         mpi: MovePathIndex,
     ) -> (Vec<MoveSite>, Vec<Location>) {
-        fn predecessor_locations<'a, 'tcx>(
-            body: &'a mir::Body<'tcx>,
+        fn predecessor_locations<'tcx>(
+            body: &mir::Body<'tcx>,
             location: Location,
-        ) -> impl Iterator<Item = Location> + Captures<'tcx> + 'a {
+        ) -> impl Iterator<Item = Location> {
             if location.statement_index == 0 {
                 let predecessors = body.basic_blocks.predecessors()[location.block].to_vec();
                 Either::Left(predecessors.into_iter().map(move |bb| body.terminator_loc(bb)))

compiler/rustc_borrowck/src/member_constraints.rs

@@ -1,7 +1,6 @@
 use std::hash::Hash;
 use std::ops::Index;
 
-use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::ty::{self, Ty};
@@ -147,9 +146,7 @@ impl<'tcx, R> MemberConstraintSet<'tcx, R>
 where
     R: Copy + Hash + Eq,
 {
-    pub(crate) fn all_indices(
-        &self,
-    ) -> impl Iterator<Item = NllMemberConstraintIndex> + Captures<'tcx> + '_ {
+    pub(crate) fn all_indices(&self) -> impl Iterator<Item = NllMemberConstraintIndex> {
         self.constraints.indices()
     }
 
@@ -159,7 +156,7 @@ where
     pub(crate) fn indices(
         &self,
         member_region_vid: R,
-    ) -> impl Iterator<Item = NllMemberConstraintIndex> + Captures<'tcx> + '_ {
+    ) -> impl Iterator<Item = NllMemberConstraintIndex> {
         let mut next = self.first_constraints.get(&member_region_vid).cloned();
         std::iter::from_fn(move || -> Option<NllMemberConstraintIndex> {
             if let Some(current) = next {

compiler/rustc_borrowck/src/polonius/loan_liveness.rs

@@ -175,7 +175,7 @@ impl LocalizedConstraintGraph {
     }
 
     /// Returns the outgoing edges of a given node, not its transitive closure.
-    fn outgoing_edges(&self, node: LocalizedNode) -> impl Iterator<Item = LocalizedNode> + use<'_> {
+    fn outgoing_edges(&self, node: LocalizedNode) -> impl Iterator<Item = LocalizedNode> {
         // The outgoing edges are:
         // - the physical edges present at this node,
         // - the materialized logical edges that exist virtually at all points for this node's

compiler/rustc_borrowck/src/region_infer/mod.rs

@@ -576,9 +576,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     }
 
     /// Returns an iterator over all the outlives constraints.
-    pub(crate) fn outlives_constraints(
-        &self,
-    ) -> impl Iterator<Item = OutlivesConstraint<'tcx>> + '_ {
+    pub(crate) fn outlives_constraints(&self) -> impl Iterator<Item = OutlivesConstraint<'tcx>> {
         self.constraints.outlives().iter().copied()
     }
 
@@ -615,10 +613,10 @@ impl<'tcx> RegionInferenceContext<'tcx> {
         self.scc_values.region_value_str(scc)
     }
 
-    pub(crate) fn placeholders_contained_in<'a>(
-        &'a self,
+    pub(crate) fn placeholders_contained_in(
+        &self,
         r: RegionVid,
-    ) -> impl Iterator<Item = ty::PlaceholderRegion> + 'a {
+    ) -> impl Iterator<Item = ty::PlaceholderRegion> {
         let scc = self.constraint_sccs.scc(r);
         self.scc_values.placeholders_contained_in(scc)
     }

compiler/rustc_borrowck/src/region_infer/reverse_sccs.rs

@@ -20,10 +20,7 @@ pub(crate) struct ReverseSccGraph {
 
 impl ReverseSccGraph {
     /// Find all universal regions that are required to outlive the given SCC.
-    pub(super) fn upper_bounds<'a>(
-        &'a self,
-        scc0: ConstraintSccIndex,
-    ) -> impl Iterator<Item = RegionVid> + 'a {
+    pub(super) fn upper_bounds(&self, scc0: ConstraintSccIndex) -> impl Iterator<Item = RegionVid> {
         let mut duplicates = FxIndexSet::default();
         graph::depth_first_search(&self.graph, scc0)
             .flat_map(move |scc1| {

compiler/rustc_borrowck/src/region_infer/values.rs

@@ -88,15 +88,15 @@ impl LivenessValues {
     }
 
     /// Iterate through each region that has a value in this set.
-    pub(crate) fn regions(&self) -> impl Iterator<Item = RegionVid> + '_ {
+    pub(crate) fn regions(&self) -> impl Iterator<Item = RegionVid> {
         self.points.as_ref().expect("use with_specific_points").rows()
     }
 
     /// Iterate through each region that has a value in this set.
     // We are passing query instability implications to the caller.
     #[rustc_lint_query_instability]
     #[allow(rustc::potential_query_instability)]
-    pub(crate) fn live_regions_unordered(&self) -> impl Iterator<Item = RegionVid> + '_ {
+    pub(crate) fn live_regions_unordered(&self) -> impl Iterator<Item = RegionVid> {
         self.live_regions.as_ref().unwrap().iter().copied()
     }
 
@@ -143,7 +143,7 @@ impl LivenessValues {
     }
 
     /// Returns an iterator of all the points where `region` is live.
-    fn live_points(&self, region: RegionVid) -> impl Iterator<Item = PointIndex> + '_ {
+    fn live_points(&self, region: RegionVid) -> impl Iterator<Item = PointIndex> {
         let Some(points) = &self.points else {
             unreachable!(
                 "Should be using LivenessValues::with_specific_points to ask whether live at a location"
@@ -340,7 +340,7 @@ impl<N: Idx> RegionValues<N> {
     }
 
     /// Returns the locations contained within a given region `r`.
-    pub(crate) fn locations_outlived_by<'a>(&'a self, r: N) -> impl Iterator<Item = Location> + 'a {
+    pub(crate) fn locations_outlived_by<'a>(&'a self, r: N) -> impl Iterator<Item = Location> {
         self.points.row(r).into_iter().flat_map(move |set| {
             set.iter()
                 .take_while(move |&p| self.location_map.point_in_range(p))
@@ -349,18 +349,15 @@ impl<N: Idx> RegionValues<N> {
     }
 
     /// Returns just the universal regions that are contained in a given region's value.
-    pub(crate) fn universal_regions_outlived_by<'a>(
-        &'a self,
-        r: N,
-    ) -> impl Iterator<Item = RegionVid> + 'a {
+    pub(crate) fn universal_regions_outlived_by(&self, r: N) -> impl Iterator<Item = RegionVid> {
         self.free_regions.row(r).into_iter().flat_map(|set| set.iter())
     }
 
     /// Returns all the elements contained in a given region's value.
-    pub(crate) fn placeholders_contained_in<'a>(
-        &'a self,
+    pub(crate) fn placeholders_contained_in(
+        &self,
         r: N,
-    ) -> impl Iterator<Item = ty::PlaceholderRegion> + 'a {
+    ) -> impl Iterator<Item = ty::PlaceholderRegion> {
         self.placeholders
             .row(r)
             .into_iter()
@@ -369,10 +366,7 @@ impl<N: Idx> RegionValues<N> {
     }
 
     /// Returns all the elements contained in a given region's value.
-    pub(crate) fn elements_contained_in<'a>(
-        &'a self,
-        r: N,
-    ) -> impl Iterator<Item = RegionElement> + 'a {
+    pub(crate) fn elements_contained_in<'a>(&'a self, r: N) -> impl Iterator<Item = RegionElement> {
         let points_iter = self.locations_outlived_by(r).map(RegionElement::Location);
 
         let free_regions_iter =

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -172,7 +172,7 @@ impl UniversalRegionRelations<'_> {
     }
 
     /// Returns the _non-transitive_ set of known `outlives` constraints between free regions.
-    pub(crate) fn known_outlives(&self) -> impl Iterator<Item = (RegionVid, RegionVid)> + '_ {
+    pub(crate) fn known_outlives(&self) -> impl Iterator<Item = (RegionVid, RegionVid)> {
         self.outlives.base_edges()
     }
 }