diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs index ab1a7461b4b9b..a3b39591f8db2 100644 --- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs +++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs @@ -6,6 +6,7 @@ use rustc_infer::infer::region_constraints::{GenericKind, VerifyBound}; use rustc_infer::infer::{self, InferCtxt, SubregionOrigin}; use rustc_middle::mir::ConstraintCategory; use rustc_middle::ty::subst::GenericArgKind; +use rustc_middle::ty::TypeFoldable; use rustc_middle::ty::{self, TyCtxt}; use rustc_span::DUMMY_SP; @@ -95,11 +96,23 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> { self.add_outlives(r1_vid, r2_vid); } - GenericArgKind::Type(t1) => { + GenericArgKind::Type(mut t1) => { // we don't actually use this for anything, but // the `TypeOutlives` code needs an origin. let origin = infer::RelateParamBound(DUMMY_SP, t1, None); + // Placeholder regions need to be converted now because it may + // create new region variables, which can't be done later when + // verifying these bounds. + if t1.has_placeholders() { + t1 = tcx.fold_regions(&t1, &mut false, |r, _| match *r { + ty::RegionKind::RePlaceholder(placeholder) => { + self.constraints.placeholder_region(self.infcx, placeholder) + } + _ => r, + }); + } + TypeOutlives::new( &mut *self, tcx, diff --git a/src/test/ui/lifetimes/issue-76168-hr-outlives.rs b/src/test/ui/lifetimes/issue-76168-hr-outlives.rs new file mode 100644 index 0000000000000..9366e94c90ff5 --- /dev/null +++ b/src/test/ui/lifetimes/issue-76168-hr-outlives.rs @@ -0,0 +1,19 @@ +// edition:2018 +// check-pass + +#![feature(unboxed_closures)] +use std::future::Future; + +async fn wrapper(f: F) +where for<'a> F: FnOnce<(&'a mut i32,)>, + for<'a> >::Output: Future + 'a +{ + let mut i = 41; + f(&mut i).await; +} + +async fn add_one(i: &mut i32) { + *i = *i + 1; +} + +fn main() {}