use rustc_infer::traits::{Obligation, SelectionError, TraitObligation};
use rustc_lint_defs::builtin::DEREF_INTO_DYN_SUPERTRAIT;
use rustc_middle::ty::print::with_no_trimmed_paths;
-use rustc_middle::ty::{self, ToPredicate, Ty, TypeFoldable};
+use rustc_middle::ty::{self, ToPredicate, Ty, TypeVisitable};
use rustc_target::spec::abi::Abi;
use crate::traits;
IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc }
};
debug!(?cause, "evaluate_stack: pushing cause");
- self.intercrate_ambiguity_causes.as_mut().unwrap().push(cause);
+ self.intercrate_ambiguity_causes.as_mut().unwrap().insert(cause);
}
}
}
self.assemble_candidates_for_unsizing(obligation, &mut candidates);
} else if lang_items.destruct_trait() == Some(def_id) {
self.assemble_const_destruct_candidates(obligation, &mut candidates);
+ } else if lang_items.transmute_trait() == Some(def_id) {
+ // User-defined transmutability impls are permitted.
+ self.assemble_candidates_from_impls(obligation, &mut candidates);
+ self.assemble_candidates_for_transmutability(obligation, &mut candidates);
} else {
if lang_items.clone_trait() == Some(def_id) {
// Same builtin conditions as `Copy`, i.e., every type which has builtin support
};
}
+ #[tracing::instrument(level = "debug", skip(self, obligation, candidates))]
+ fn assemble_candidates_for_transmutability(
+ &mut self,
+ obligation: &TraitObligation<'tcx>,
+ candidates: &mut SelectionCandidateSet<'tcx>,
+ ) {
+ if obligation.has_param_types_or_consts() {
+ return;
+ }
+
+ if obligation.has_infer_types_or_consts() {
+ candidates.ambiguous = true;
+ return;
+ }
+
+ candidates.vec.push(TransmutabilityCandidate);
+ }
+
#[tracing::instrument(level = "debug", skip(self, obligation, candidates))]
fn assemble_candidates_for_trait_alias(
&mut self,