};
use rustc_session::Limit;
use rustc_span::def_id::LOCAL_CRATE;
-use rustc_span::symbol::{kw, sym};
+use rustc_span::symbol::sym;
use rustc_span::{ExpnKind, Span, DUMMY_SP};
use std::fmt;
use std::iter;
trait_ref,
obligation.cause.body_id,
&mut err,
+ true,
) {
// This is *almost* equivalent to
// `obligation.cause.code().peel_derives()`, but it gives us the
trait_ref,
obligation.cause.body_id,
&mut err,
+ true,
);
}
}
&& self.fallback_has_occurred
{
let predicate = trait_predicate.map_bound(|trait_pred| {
- trait_pred.with_self_type(self.tcx, self.tcx.mk_unit())
+ trait_pred.with_self_ty(self.tcx, self.tcx.mk_unit())
});
let unit_obligation = obligation.with(tcx, predicate);
if self.predicate_may_hold(&unit_obligation) {
trait_ref: ty::PolyTraitRef<'tcx>,
body_id: hir::HirId,
err: &mut Diagnostic,
+ other: bool,
) -> bool;
/// Gets the parent trait chain start
trait_ref: ty::PolyTraitRef<'tcx>,
body_id: hir::HirId,
err: &mut Diagnostic,
+ other: bool,
) -> bool {
+ let other = if other { "other " } else { "" };
let report = |mut candidates: Vec<TraitRef<'tcx>>, err: &mut Diagnostic| {
candidates.sort();
candidates.dedup();
candidates.dedup();
let end = if candidates.len() <= 9 { candidates.len() } else { 8 };
err.help(&format!(
- "the following other types implement trait `{}`:{}{}",
+ "the following {other}types implement trait `{}`:{}{}",
trait_ref.print_only_trait_path(),
candidates[..end].join(""),
if len > 9 { format!("\nand {} others", len - 8) } else { String::new() }
param_env: ty::ParamEnv<'tcx>,
trait_ref_and_ty: ty::Binder<'tcx, (ty::TraitPredicate<'tcx>, Ty<'tcx>)>,
) -> PredicateObligation<'tcx> {
- let trait_pred = trait_ref_and_ty
- .map_bound(|(tr, new_self_ty)| tr.with_self_type(self.tcx, new_self_ty));
+ let trait_pred =
+ trait_ref_and_ty.map_bound(|(tr, new_self_ty)| tr.with_self_ty(self.tcx, new_self_ty));
Obligation::new(self.tcx, ObligationCause::dummy(), param_env, trait_pred)
}
trait_ref.skip_binder().substs.types().any(|t| !t.is_ty_infer());
// It doesn't make sense to talk about applicable impls if there are more
// than a handful of them.
- if impls.len() > 1 && impls.len() < 5 && has_non_region_infer {
+ if impls.len() > 1 && impls.len() < 10 && has_non_region_infer {
self.annotate_source_of_ambiguity(&mut err, &impls, predicate);
} else {
if self.tainted_by_errors().is_some() {
return;
}
err.note(&format!("cannot satisfy `{}`", predicate));
+ let impl_candidates = self.find_similar_impl_candidates(
+ predicate.to_opt_poly_trait_pred().unwrap(),
+ );
+ if impl_candidates.len() < 10 {
+ self.report_similar_impl_candidates(
+ impl_candidates,
+ trait_ref,
+ body_id.map(|id| id.hir_id).unwrap_or(obligation.cause.body_id),
+ &mut err,
+ false,
+ );
+ }
}
}
_ => {
}
}
- if let ObligationCauseCode::ItemObligation(def_id) | ObligationCauseCode::ExprItemObligation(def_id, ..) = *obligation.cause.code() {
- self.suggest_fully_qualified_path(&mut err, def_id, span, trait_ref.def_id());
- } else if let Ok(snippet) = &self.tcx.sess.source_map().span_to_snippet(span)
- && let ObligationCauseCode::BindingObligation(def_id, _) | ObligationCauseCode::ExprBindingObligation(def_id, ..)
- = *obligation.cause.code()
+ if let ObligationCauseCode::ItemObligation(def_id)
+ | ObligationCauseCode::ExprItemObligation(def_id, ..) = *obligation.cause.code()
{
- let generics = self.tcx.generics_of(def_id);
- if generics.params.iter().any(|p| p.name != kw::SelfUpper)
- && !snippet.ends_with('>')
- && !generics.has_impl_trait()
- && !self.tcx.is_fn_trait(def_id)
- {
- // FIXME: To avoid spurious suggestions in functions where type arguments
- // where already supplied, we check the snippet to make sure it doesn't
- // end with a turbofish. Ideally we would have access to a `PathSegment`
- // instead. Otherwise we would produce the following output:
- //
- // error[E0283]: type annotations needed
- // --> $DIR/issue-54954.rs:3:24
- // |
- // LL | const ARR_LEN: usize = Tt::const_val::<[i8; 123]>();
- // | ^^^^^^^^^^^^^^^^^^^^^^^^^^
- // | |
- // | cannot infer type
- // | help: consider specifying the type argument
- // | in the function call:
- // | `Tt::const_val::<[i8; 123]>::<T>`
- // ...
- // LL | const fn const_val<T: Sized>() -> usize {
- // | - required by this bound in `Tt::const_val`
- // |
- // = note: cannot satisfy `_: Tt`
-
- // Clear any more general suggestions in favor of our specific one
- err.clear_suggestions();
-
- err.span_suggestion_verbose(
- span.shrink_to_hi(),
- &format!(
- "consider specifying the type argument{} in the function call",
- pluralize!(generics.params.len()),
- ),
- format!(
- "::<{}>",
- generics
- .params
- .iter()
- .map(|p| p.name.to_string())
- .collect::<Vec<String>>()
- .join(", ")
- ),
- Applicability::HasPlaceholders,
- );
- }
+ self.suggest_fully_qualified_path(&mut err, def_id, span, trait_ref.def_id());
}
if let (Some(body_id), Some(ty::subst::GenericArgKind::Type(_))) =