Auto merge of #128336 - Bryanskiy:inst-binder-with-fresh, r=lcnr

Use Vec in instantiate_binder_with_fresh_vars

`FxHashMap`  was replaced with a pre-computed `Vec` of infer vars.

r? `@lcnr`
This commit is contained in:
bors 2024-07-30 08:15:17 +00:00
commit e69c19ea0b

View File

@ -13,7 +13,7 @@
pub use relate::combine::{CombineFields, PredicateEmittingRelation};
pub use relate::StructurallyRelateAliases;
use rustc_data_structures::captures::Captures;
use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
use rustc_data_structures::sync::Lrc;
use rustc_data_structures::undo_log::Rollback;
use rustc_data_structures::unify as ut;
@ -1318,38 +1318,36 @@ pub fn instantiate_binder_with_fresh_vars<T>(
return inner;
}
struct ToFreshVars<'a, 'tcx> {
infcx: &'a InferCtxt<'tcx>,
span: Span,
lbrct: BoundRegionConversionTime,
map: FxHashMap<ty::BoundVar, ty::GenericArg<'tcx>>,
let bound_vars = value.bound_vars();
let mut args = Vec::with_capacity(bound_vars.len());
for bound_var_kind in bound_vars {
let arg: ty::GenericArg<'_> = match bound_var_kind {
ty::BoundVariableKind::Ty(_) => self.next_ty_var(span).into(),
ty::BoundVariableKind::Region(br) => {
self.next_region_var(BoundRegion(span, br, lbrct)).into()
}
ty::BoundVariableKind::Const => self.next_const_var(span).into(),
};
args.push(arg);
}
impl<'tcx> BoundVarReplacerDelegate<'tcx> for ToFreshVars<'_, 'tcx> {
struct ToFreshVars<'tcx> {
args: Vec<ty::GenericArg<'tcx>>,
}
impl<'tcx> BoundVarReplacerDelegate<'tcx> for ToFreshVars<'tcx> {
fn replace_region(&mut self, br: ty::BoundRegion) -> ty::Region<'tcx> {
self.map
.entry(br.var)
.or_insert_with(|| {
self.infcx
.next_region_var(BoundRegion(self.span, br.kind, self.lbrct))
.into()
})
.expect_region()
self.args[br.var.index()].expect_region()
}
fn replace_ty(&mut self, bt: ty::BoundTy) -> Ty<'tcx> {
self.map
.entry(bt.var)
.or_insert_with(|| self.infcx.next_ty_var(self.span).into())
.expect_ty()
self.args[bt.var.index()].expect_ty()
}
fn replace_const(&mut self, bv: ty::BoundVar) -> ty::Const<'tcx> {
self.map
.entry(bv)
.or_insert_with(|| self.infcx.next_const_var(self.span).into())
.expect_const()
self.args[bv.index()].expect_const()
}
}
let delegate = ToFreshVars { infcx: self, span, lbrct, map: Default::default() };
let delegate = ToFreshVars { args };
self.tcx.replace_bound_vars_uncached(value, delegate)
}