diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index 4ca83904f47..80d0faca670 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -3592,7 +3592,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // Extract `<U as Deref>::Target` assoc type and check that it is `T` && let Some(deref_target_did) = tcx.lang_items().deref_target() && let projection = tcx.mk_projection(deref_target_did, tcx.mk_substs(&[ty::GenericArg::from(found_ty)])) - && let Ok(deref_target) = tcx.try_normalize_erasing_regions(param_env, projection) + && let InferOk { value: deref_target, obligations } = infcx.at(&ObligationCause::dummy(), param_env).normalize(projection) + && obligations.iter().all(|obligation| infcx.predicate_must_hold_modulo_regions(obligation)) && infcx.can_eq(param_env, deref_target, target_ty) { let help = if let hir::Mutability::Mut = needs_mut diff --git a/tests/ui/mismatched_types/suggest-option-asderef-inference-var.rs b/tests/ui/mismatched_types/suggest-option-asderef-inference-var.rs new file mode 100644 index 00000000000..5febbbe392b --- /dev/null +++ b/tests/ui/mismatched_types/suggest-option-asderef-inference-var.rs @@ -0,0 +1,9 @@ +fn deref_int(a: &i32) -> i32 { + *a +} + +fn main() { + // https://github.com/rust-lang/rust/issues/112293 + let _has_inference_vars: Option<i32> = Some(0).map(deref_int); + //~^ ERROR type mismatch in function arguments +} diff --git a/tests/ui/mismatched_types/suggest-option-asderef-inference-var.stderr b/tests/ui/mismatched_types/suggest-option-asderef-inference-var.stderr new file mode 100644 index 00000000000..71c4729e310 --- /dev/null +++ b/tests/ui/mismatched_types/suggest-option-asderef-inference-var.stderr @@ -0,0 +1,24 @@ +error[E0631]: type mismatch in function arguments + --> $DIR/suggest-option-asderef-inference-var.rs:7:56 + | +LL | fn deref_int(a: &i32) -> i32 { + | ---------------------------- found signature defined here +... +LL | let _has_inference_vars: Option<i32> = Some(0).map(deref_int); + | --- ^^^^^^^^^ expected due to this + | | + | required by a bound introduced by this call + | + = note: expected function signature `fn({integer}) -> _` + found function signature `for<'a> fn(&'a i32) -> _` +note: required by a bound in `Option::<T>::map` + --> $SRC_DIR/core/src/option.rs:LL:COL +help: do not borrow the argument + | +LL - fn deref_int(a: &i32) -> i32 { +LL + fn deref_int(a: i32) -> i32 { + | + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0631`.