rust-lang/rust
1
0
Fork 0
Code Issues Pull Requests Actions 2 Packages Projects Releases Wiki Activity

Point at overlapping impls when type annotations are needed

Browse Source
This commit is contained in:
Esteban Kuber
2021-10-01 13:05:17 +00:00
parent ed08a67566
commit ef212e7fb3
29 changed files with 629 additions and 88 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
compiler/rustc_trait_selection/src/traits/select/mod.rs
View File

@@ -357,18 +357,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
&mut self,
obligation: &TraitObligation<'tcx>,
) -> SelectionResult<'tcx, Selection<'tcx>> {
debug_assert!(!obligation.predicate.has_escaping_bound_vars());
let pec = &ProvisionalEvaluationCache::default();
let stack = self.push_stack(TraitObligationStackList::empty(pec), obligation);
let candidate = match self.candidate_from_obligation(&stack) {
let candidate = match self.select_from_obligation(obligation) {
Err(SelectionError::Overflow) => {
// In standard mode, overflow must have been caught and reported
// earlier.
assert!(self.query_mode == TraitQueryMode::Canonical);
return Err(SelectionError::Overflow);
}
Err(SelectionError::Ambiguous(_)) => {
return Ok(None);
}
Err(e) => {
return Err(e);
}
@@ -391,6 +389,18 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
crate fn select_from_obligation(
&mut self,
obligation: &TraitObligation<'tcx>,
) -> SelectionResult<'tcx, SelectionCandidate<'tcx>> {
debug_assert!(!obligation.predicate.has_escaping_bound_vars());
let pec = &ProvisionalEvaluationCache::default();
let stack = self.push_stack(TraitObligationStackList::empty(pec), obligation);
self.candidate_from_obligation(&stack)
}
///////////////////////////////////////////////////////////////////////////
// EVALUATION
//
@@ -915,6 +925,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
match self.candidate_from_obligation(stack) {
Ok(Some(c)) => self.evaluate_candidate(stack, &c),
Err(SelectionError::Ambiguous(_)) => Ok(EvaluatedToAmbig),
Ok(None) => Ok(EvaluatedToAmbig),
Err(Overflow) => Err(OverflowError::Canonical),
Err(ErrorReporting) => Err(OverflowError::ErrorReporting),