diff options
| -rw-r--r-- | compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs | 62 |
1 files changed, 30 insertions, 32 deletions
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs index e0ddb90c33b..7534e432f11 100644 --- a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs +++ b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs @@ -310,7 +310,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { .iter() .filter(|field| { let field_ty = field.ty(self.tcx, identity_substs); - Self::find_param_in_ty(field_ty.into(), param_to_point_at) + find_param_in_ty(field_ty.into(), param_to_point_at) }) .collect(); @@ -356,7 +356,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { .inputs() .iter() .enumerate() - .filter(|(_, ty)| Self::find_param_in_ty((**ty).into(), param_to_point_at)) + .filter(|(_, ty)| find_param_in_ty((**ty).into(), param_to_point_at)) .collect(); // If there's one field that references the given generic, great! if let [(idx, _)] = args_referencing_param.as_slice() @@ -579,8 +579,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Find out which of `in_ty_elements` refer to `param`. // FIXME: It may be better to take the first if there are multiple, // just so that the error points to a smaller expression. - let Some((drill_expr, drill_ty)) = Self::is_iterator_singleton(expr_elements.iter().zip( in_ty_elements.iter()).filter(|(_expr_elem, in_ty_elem)| { - Self::find_param_in_ty((*in_ty_elem).into(), param) + let Some((drill_expr, drill_ty)) = is_iterator_singleton(expr_elements.iter().zip( in_ty_elements.iter()).filter(|(_expr_elem, in_ty_elem)| { + find_param_in_ty((*in_ty_elem).into(), param) })) else { // The param is not mentioned, or it is mentioned in multiple indexes. return Err(expr); @@ -628,10 +628,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // We need to know which of the generic parameters mentions our target param. // We expect that at least one of them does, since it is expected to be mentioned. let Some((drill_generic_index, generic_argument_type)) = - Self::is_iterator_singleton( + is_iterator_singleton( in_ty_adt_generic_args.iter().enumerate().filter( |(_index, in_ty_generic)| { - Self::find_param_in_ty(*in_ty_generic, param) + find_param_in_ty(*in_ty_generic, param) }, ), ) else { @@ -751,10 +751,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // We need to know which of the generic parameters mentions our target param. // We expect that at least one of them does, since it is expected to be mentioned. let Some((drill_generic_index, generic_argument_type)) = - Self::is_iterator_singleton( + is_iterator_singleton( in_ty_adt_generic_args.iter().enumerate().filter( |(_index, in_ty_generic)| { - Self::find_param_in_ty(*in_ty_generic, param) + find_param_in_ty(*in_ty_generic, param) }, ), ) else { @@ -793,14 +793,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // outer contextual information. // (1) Find the (unique) field index which mentions the type in our constraint: - let Some((field_index, field_type)) = Self::is_iterator_singleton( + let Some((field_index, field_type)) = is_iterator_singleton( in_ty_adt .variant_with_id(variant_def_id) .fields .iter() .map(|field| field.ty(self.tcx, *in_ty_adt_generic_args)) .enumerate() - .filter(|(_index, field_type)| Self::find_param_in_ty((*field_type).into(), param)) + .filter(|(_index, field_type)| find_param_in_ty((*field_type).into(), param)) ) else { return Err(expr); }; @@ -833,20 +833,20 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { Err(expr) } +} - // FIXME: This can be made into a private, non-impl function later. - /// Traverses the given ty (either a `ty::Ty` or a `ty::GenericArg`) and searches for references - /// to the given `param_to_point_at`. Returns `true` if it finds any use of the param. - pub fn find_param_in_ty( - ty: ty::GenericArg<'tcx>, - param_to_point_at: ty::GenericArg<'tcx>, - ) -> bool { - let mut walk = ty.walk(); - while let Some(arg) = walk.next() { - if arg == param_to_point_at { - return true; - } - if let ty::GenericArgKind::Type(ty) = arg.unpack() +/// Traverses the given ty (either a `ty::Ty` or a `ty::GenericArg`) and searches for references +/// to the given `param_to_point_at`. Returns `true` if it finds any use of the param. +fn find_param_in_ty<'tcx>( + ty: ty::GenericArg<'tcx>, + param_to_point_at: ty::GenericArg<'tcx>, +) -> bool { + let mut walk = ty.walk(); + while let Some(arg) = walk.next() { + if arg == param_to_point_at { + return true; + } + if let ty::GenericArgKind::Type(ty) = arg.unpack() && let ty::Alias(ty::Projection, ..) = ty.kind() { // This logic may seem a bit strange, but typically when @@ -857,16 +857,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // in some UI tests. walk.skip_current_subtree(); } - } - false } + false +} - // FIXME: This can be made into a private, non-impl function later. - /// Returns `Some(iterator.next())` if it has exactly one item, and `None` otherwise. - pub fn is_iterator_singleton<T>(mut iterator: impl Iterator<Item = T>) -> Option<T> { - match (iterator.next(), iterator.next()) { - (_, Some(_)) => None, - (first, _) => first, - } +/// Returns `Some(iterator.next())` if it has exactly one item, and `None` otherwise. +fn is_iterator_singleton<T>(mut iterator: impl Iterator<Item = T>) -> Option<T> { + match (iterator.next(), iterator.next()) { + (_, Some(_)) => None, + (first, _) => first, } } |