diff options
| -rw-r--r-- | src/librustc/infer/canonical/query_result.rs | 120 | ||||
| -rw-r--r-- | src/librustc/infer/equate.rs | 6 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/mod.rs | 17 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/need_type_info.rs | 8 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs | 10 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs | 53 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs | 94 | ||||
| -rw-r--r-- | src/librustc/infer/error_reporting/nice_region_error/util.rs | 19 | ||||
| -rw-r--r-- | src/librustc/infer/lexical_region_resolve/graphviz.rs | 20 | ||||
| -rw-r--r-- | src/librustc/infer/lexical_region_resolve/mod.rs | 4 | ||||
| -rw-r--r-- | src/librustc/infer/opaque_types/mod.rs | 1 | ||||
| -rw-r--r-- | src/librustc/infer/region_constraints/mod.rs | 7 | ||||
| -rw-r--r-- | src/librustc/infer/resolve.rs | 4 | ||||
| -rw-r--r-- | src/librustc/infer/type_variable.rs | 7 |
14 files changed, 170 insertions, 200 deletions
diff --git a/src/librustc/infer/canonical/query_result.rs b/src/librustc/infer/canonical/query_result.rs index 65d42c0888d..a327f1f5c9d 100644 --- a/src/librustc/infer/canonical/query_result.rs +++ b/src/librustc/infer/canonical/query_result.rs @@ -135,10 +135,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { ); // Select everything, returning errors. - let true_errors = match fulfill_cx.select_where_possible(self) { - Ok(()) => vec![], - Err(errors) => errors, - }; + let true_errors = fulfill_cx.select_where_possible(self).err().unwrap_or_else(Vec::new); debug!("true_errors = {:#?}", true_errors); if !true_errors.is_empty() { @@ -148,10 +145,7 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { } // Anything left unselected *now* must be an ambiguity. - let ambig_errors = match fulfill_cx.select_all_or_error(self) { - Ok(()) => vec![], - Err(errors) => errors, - }; + let ambig_errors = fulfill_cx.select_all_or_error(self).err().unwrap_or_else(Vec::new); debug!("ambig_errors = {:#?}", ambig_errors); let region_obligations = self.take_registered_region_obligations(); @@ -316,16 +310,18 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { } // ...also include the other query region constraints from the query. - output_query_region_constraints.reserve(query_result.value.region_constraints.len()); - for r_c in query_result.value.region_constraints.iter() { - let &ty::OutlivesPredicate(k1, r2) = r_c.skip_binder(); // reconstructed below - let k1 = substitute_value(self.tcx, &result_subst, &k1); - let r2 = substitute_value(self.tcx, &result_subst, &r2); - if k1 != r2.into() { - output_query_region_constraints - .push(ty::Binder::bind(ty::OutlivesPredicate(k1, r2))); - } - } + output_query_region_constraints.extend( + query_result.value.region_constraints.iter().filter_map(|r_c| { + let &ty::OutlivesPredicate(k1, r2) = r_c.skip_binder(); // reconstructed below + let k1 = substitute_value(self.tcx, &result_subst, &k1); + let r2 = substitute_value(self.tcx, &result_subst, &r2); + if k1 != r2.into() { + Some(ty::Binder::bind(ty::OutlivesPredicate(k1, r2))) + } else { + None + } + }) + ); let user_result: R = query_result.substitute_projected(self.tcx, &result_subst, |q_r| &q_r.value); @@ -448,10 +444,9 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { .variables .iter() .enumerate() - .map(|(index, info)| match opt_values[CanonicalVar::new(index)] { - Some(k) => k, - None => self.fresh_inference_var_for_canonical_var(cause.span, *info), - }) + .map(|(index, info)| opt_values[CanonicalVar::new(index)].unwrap_or_else(|| + self.fresh_inference_var_for_canonical_var(cause.span, *info) + )) .collect(), }; @@ -504,24 +499,22 @@ impl<'cx, 'gcx, 'tcx> InferCtxt<'cx, 'gcx, 'tcx> { let ty::OutlivesPredicate(k1, r2) = constraint.skip_binder(); // restored below let k1 = substitute_value(self.tcx, result_subst, k1); let r2 = substitute_value(self.tcx, result_subst, r2); - match k1.unpack() { - UnpackedKind::Lifetime(r1) => Obligation::new( - cause.clone(), - param_env, - ty::Predicate::RegionOutlives(ty::Binder::dummy( - ty::OutlivesPredicate(r1, r2), + + Obligation::new( + cause.clone(), + param_env, + match k1.unpack() { + UnpackedKind::Lifetime(r1) => ty::Predicate::RegionOutlives( + ty::Binder::dummy( + ty::OutlivesPredicate(r1, r2) )), - ), - - UnpackedKind::Type(t1) => Obligation::new( - cause.clone(), - param_env, - ty::Predicate::TypeOutlives(ty::Binder::dummy(ty::OutlivesPredicate( - t1, r2, - ))), - ), - } - }), + UnpackedKind::Type(t1) => ty::Predicate::TypeOutlives( + ty::Binder::dummy(ty::OutlivesPredicate( + t1, r2 + ))) + } + ) + }) ) as Box<dyn Iterator<Item = _>> } @@ -583,31 +576,30 @@ pub fn make_query_outlives<'tcx>( assert!(verifys.is_empty()); assert!(givens.is_empty()); - let mut outlives: Vec<_> = constraints - .into_iter() - .map(|(k, _)| match *k { - // Swap regions because we are going from sub (<=) to outlives - // (>=). - Constraint::VarSubVar(v1, v2) => ty::OutlivesPredicate( - tcx.mk_region(ty::ReVar(v2)).into(), - tcx.mk_region(ty::ReVar(v1)), - ), - Constraint::VarSubReg(v1, r2) => { - ty::OutlivesPredicate(r2.into(), tcx.mk_region(ty::ReVar(v1))) - } - Constraint::RegSubVar(r1, v2) => { - ty::OutlivesPredicate(tcx.mk_region(ty::ReVar(v2)).into(), r1) - } - Constraint::RegSubReg(r1, r2) => ty::OutlivesPredicate(r2.into(), r1), - }) - .map(ty::Binder::dummy) // no bound regions in the code above - .collect(); - - outlives.extend( - outlives_obligations - .map(|(ty, r)| ty::OutlivesPredicate(ty.into(), r)) - .map(ty::Binder::dummy), // no bound regions in the code above - ); + let outlives: Vec<_> = constraints + .into_iter() + .map(|(k, _)| match *k { + // Swap regions because we are going from sub (<=) to outlives + // (>=). + Constraint::VarSubVar(v1, v2) => ty::OutlivesPredicate( + tcx.mk_region(ty::ReVar(v2)).into(), + tcx.mk_region(ty::ReVar(v1)), + ), + Constraint::VarSubReg(v1, r2) => { + ty::OutlivesPredicate(r2.into(), tcx.mk_region(ty::ReVar(v1))) + } + Constraint::RegSubVar(r1, v2) => { + ty::OutlivesPredicate(tcx.mk_region(ty::ReVar(v2)).into(), r1) + } + Constraint::RegSubReg(r1, r2) => ty::OutlivesPredicate(r2.into(), r1), + }) + .map(ty::Binder::dummy) // no bound regions in the code above + .chain( + outlives_obligations + .map(|(ty, r)| ty::OutlivesPredicate(ty.into(), r)) + .map(ty::Binder::dummy), // no bound regions in the code above + ) + .collect(); outlives } diff --git a/src/librustc/infer/equate.rs b/src/librustc/infer/equate.rs index 26eb2ffbf6a..854960492c9 100644 --- a/src/librustc/infer/equate.rs +++ b/src/librustc/infer/equate.rs @@ -77,24 +77,22 @@ impl<'combine, 'infcx, 'gcx, 'tcx> TypeRelation<'infcx, 'gcx, 'tcx> match (&a.sty, &b.sty) { (&ty::Infer(TyVar(a_id)), &ty::Infer(TyVar(b_id))) => { infcx.type_variables.borrow_mut().equate(a_id, b_id); - Ok(a) } (&ty::Infer(TyVar(a_id)), _) => { self.fields.instantiate(b, RelationDir::EqTo, a_id, self.a_is_expected)?; - Ok(a) } (_, &ty::Infer(TyVar(b_id))) => { self.fields.instantiate(a, RelationDir::EqTo, b_id, self.a_is_expected)?; - Ok(a) } _ => { self.fields.infcx.super_combine_tys(self, a, b)?; - Ok(a) } } + + Ok(a) } fn regions(&mut self, a: ty::Region<'tcx>, b: ty::Region<'tcx>) diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs index 09059090e2e..a68241ff2c0 100644 --- a/src/librustc/infer/error_reporting/mod.rs +++ b/src/librustc/infer/error_reporting/mod.rs @@ -406,10 +406,10 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { errors.clone() } else { errors - .iter() - .filter(|&e| !is_bound_failure(e)) - .cloned() - .collect() + .iter() + .filter(|&e| !is_bound_failure(e)) + .cloned() + .collect() }; // sort the errors by span, for better error message stability. @@ -455,11 +455,10 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { TypeError::Sorts(ref exp_found) => { // if they are both "path types", there's a chance of ambiguity // due to different versions of the same crate - match (&exp_found.expected.sty, &exp_found.found.sty) { - (&ty::Adt(exp_adt, _), &ty::Adt(found_adt, _)) => { - report_path_match(err, exp_adt.did, found_adt.did); - } - _ => (), + if let (&ty::Adt(exp_adt, _), &ty::Adt(found_adt, _)) + = (&exp_found.expected.sty, &exp_found.found.sty) + { + report_path_match(err, exp_adt.did, found_adt.did); } } TypeError::Traits(ref exp_found) => { diff --git a/src/librustc/infer/error_reporting/need_type_info.rs b/src/librustc/infer/error_reporting/need_type_info.rs index 505b1bc032d..efb316243fa 100644 --- a/src/librustc/infer/error_reporting/need_type_info.rs +++ b/src/librustc/infer/error_reporting/need_type_info.rs @@ -100,7 +100,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { let mut labels = vec![( span, if &name == "_" { - "cannot infer type".to_string() + "cannot infer type".to_owned() } else { format!("cannot infer type for `{}`", name) }, @@ -138,7 +138,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { // ``` labels.clear(); labels.push( - (pattern.span, "consider giving this closure parameter a type".to_string())); + (pattern.span, "consider giving this closure parameter a type".to_owned())); } else if let Some(pattern) = local_visitor.found_local_pattern { if let Some(simple_ident) = pattern.simple_ident() { match pattern.span.compiler_desugaring_kind() { @@ -146,12 +146,12 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { format!("consider giving `{}` a type", simple_ident))), Some(CompilerDesugaringKind::ForLoop) => labels.push(( pattern.span, - "the element type for this iterator is not specified".to_string(), + "the element type for this iterator is not specified".to_owned(), )), _ => {} } } else { - labels.push((pattern.span, "consider giving the pattern a type".to_string())); + labels.push((pattern.span, "consider giving the pattern a type".to_owned())); } } diff --git a/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs b/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs index 97b1978cb2e..1f84c73a715 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/different_lifetimes.rs @@ -113,12 +113,12 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { (None, None) => { let (main_label_1, span_label_1) = if ty_sup.id == ty_sub.id { ( - "this type is declared with multiple lifetimes...".to_string(), - "...but data with one lifetime flows into the other here".to_string() + "this type is declared with multiple lifetimes...".to_owned(), + "...but data with one lifetime flows into the other here".to_owned() ) } else { ( - "these two types are declared with different lifetimes...".to_string(), + "these two types are declared with different lifetimes...".to_owned(), format!( "...but data{} flows{} here", span_label_var1, @@ -133,7 +133,7 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { ty_sub.span, ret_span, "this parameter and the return type are declared \ - with different lifetimes...".to_string() + with different lifetimes...".to_owned() , format!("...but data{} is returned here", span_label_var1), ), @@ -141,7 +141,7 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { ty_sup.span, ret_span, "this parameter and the return type are declared \ - with different lifetimes...".to_string() + with different lifetimes...".to_owned() , format!("...but data{} is returned here", span_label_var1), ), diff --git a/src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs b/src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs index 5c27cdb6fb5..009a8235681 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs @@ -58,18 +58,17 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { &RegionKind::ReFree(ref free_region)) = (&sub_origin, sup_region) { let hir = &self.tcx.hir; if let Some(node_id) = hir.as_local_node_id(free_region.scope) { - match hir.get(node_id) { - Node::Expr(Expr { - node: Closure(_, _, _, closure_span, None), - .. - }) => { - let sup_sp = sup_origin.span(); - let origin_sp = origin.span(); - let mut err = self.tcx.sess.struct_span_err( - sup_sp, - "borrowed data cannot be stored outside of its closure"); - err.span_label(sup_sp, "cannot be stored outside of its closure"); - if origin_sp == sup_sp || origin_sp.contains(sup_sp) { + if let Node::Expr(Expr { + node: Closure(_, _, _, closure_span, None), + .. + }) = hir.get(node_id) { + let sup_sp = sup_origin.span(); + let origin_sp = origin.span(); + let mut err = self.tcx.sess.struct_span_err( + sup_sp, + "borrowed data cannot be stored outside of its closure"); + err.span_label(sup_sp, "cannot be stored outside of its closure"); + if origin_sp == sup_sp || origin_sp.contains(sup_sp) { // // sup_sp == origin.span(): // // let mut x = None; @@ -87,11 +86,11 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { // ------------ ... because it cannot outlive this closure // f = Some(x); // ^ cannot be stored outside of its closure - err.span_label(*external_span, - "borrowed data cannot be stored into here..."); - err.span_label(*closure_span, - "...because it cannot outlive this closure"); - } else { + err.span_label(*external_span, + "borrowed data cannot be stored into here..."); + err.span_label(*closure_span, + "...because it cannot outlive this closure"); + } else { // FIXME: the wording for this case could be much improved // // let mut lines_to_use: Vec<&CrateId> = Vec::new(); @@ -102,18 +101,16 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { // ...so that variable is valid at time of its declaration // lines_to_use.push(installed_id); // ^^^^^^^^^^^^ cannot be stored outside of its closure - err.span_label(origin_sp, - "cannot infer an appropriate lifetime..."); - err.span_label(*external_span, - "...so that variable is valid at time of its \ - declaration"); - err.span_label(*closure_span, - "borrowed data cannot outlive this closure"); - } - err.emit(); - return Some(ErrorReported); + err.span_label(origin_sp, + "cannot infer an appropriate lifetime..."); + err.span_label(*external_span, + "...so that variable is valid at time of its \ + declaration"); + err.span_label(*closure_span, + "borrowed data cannot outlive this closure"); } - _ => {} + err.emit(); + return Some(ErrorReported); } } } diff --git a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs index 3393eb65089..766173bf662 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/static_impl_trait.rs @@ -20,64 +20,62 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { /// Print the error message for lifetime errors when the return type is a static impl Trait. pub(super) fn try_report_static_impl_trait(&self) -> Option<ErrorReported> { if let Some(ref error) = self.error { - match error.clone() { - RegionResolutionError::SubSupConflict( + if let RegionResolutionError::SubSupConflict( var_origin, sub_origin, sub_r, sup_origin, sup_r, - ) => { - let anon_reg_sup = self.tcx.is_suitable_region(sup_r)?; - if sub_r == &RegionKind::ReStatic && - self.tcx.return_type_impl_trait(anon_reg_sup.def_id).is_some() - { - let sp = var_origin.span(); - let return_sp = sub_origin.span(); - let mut err = self.tcx.sess.struct_span_err( - sp, - "cannot infer an appropriate lifetime", + ) = error.clone() + { + let anon_reg_sup = self.tcx.is_suitable_region(sup_r)?; + if sub_r == &RegionKind::ReStatic && + self.tcx.return_type_impl_trait(anon_reg_sup.def_id).is_some() + { + let sp = var_origin.span(); + let return_sp = sub_origin.span(); + let mut err = self.tcx.sess.struct_span_err( + sp, + "cannot infer an appropriate lifetime", + ); + err.span_label( + return_sp, + "this return type evaluates to the `'static` lifetime...", + ); + err.span_label( + sup_origin.span(), + "...but this borrow...", + ); + + let (lifetime, lt_sp_opt) = self.tcx.msg_span_from_free_region(sup_r); + if let Some(lifetime_sp) = lt_sp_opt { + err.span_note( + lifetime_sp, + &format!("...can't outlive {}", lifetime), ); - err.span_label( + } + + let lifetime_name = match sup_r { + RegionKind::ReFree(FreeRegion { + bound_region: BoundRegion::BrNamed(_, ref name), .. + }) => name.to_string(), + _ => "'_".to_owned(), + }; + if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(return_sp) { + err.span_suggestion_with_applicability( return_sp, - "this return type evaluates to the `'static` lifetime...", + &format!( + "you can add a constraint to the return type to make it last \ + less than `'static` and match {}", + lifetime, + ), + format!("{} + {}", snippet, lifetime_name), + Applicability::Unspecified, ); - err.span_label( - sup_origin.span(), - "...but this borrow...", - ); - - let (lifetime, lt_sp_opt) = self.tcx.msg_span_from_free_region(sup_r); - if let Some(lifetime_sp) = lt_sp_opt { - err.span_note( - lifetime_sp, - &format!("...can't outlive {}", lifetime), - ); - } - - let lifetime_name = match sup_r { - RegionKind::ReFree(FreeRegion { - bound_region: BoundRegion::BrNamed(_, ref name), .. - }) => name.to_string(), - _ => "'_".to_owned(), - }; - if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(return_sp) { - err.span_suggestion_with_applicability( - return_sp, - &format!( - "you can add a constraint to the return type to make it last \ - less than `'static` and match {}", - lifetime, - ), - format!("{} + {}", snippet, lifetime_name), - Applicability::Unspecified, - ); - } - err.emit(); - return Some(ErrorReported); } + err.emit(); + return Some(ErrorReported); } - _ => {} } } None diff --git a/src/librustc/infer/error_reporting/nice_region_error/util.rs b/src/librustc/infer/error_reporting/nice_region_error/util.rs index a6efb5e6783..013c02f75b8 100644 --- a/src/librustc/infer/error_reporting/nice_region_error/util.rs +++ b/src/librustc/infer/error_reporting/nice_region_error/util.rs @@ -119,16 +119,13 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { decl: &hir::FnDecl, ) -> Option<Span> { let ret_ty = self.tcx.type_of(scope_def_id); - match ret_ty.sty { - ty::FnDef(_, _) => { - let sig = ret_ty.fn_sig(self.tcx); - let late_bound_regions = self.tcx - .collect_referenced_late_bound_regions(&sig.output()); - if late_bound_regions.iter().any(|r| *r == br) { - return Some(decl.output.span()); - } + if let ty::FnDef(_, _) = ret_ty.sty { + let sig = ret_ty.fn_sig(self.tcx); + let late_bound_regions = self.tcx + .collect_referenced_late_bound_regions(&sig.output()); + if late_bound_regions.iter().any(|r| *r == br) { + return Some(decl.output.span()); } - _ => {} } None } @@ -140,8 +137,8 @@ impl<'a, 'gcx, 'tcx> NiceRegionError<'a, 'gcx, 'tcx> { pub(super) fn is_self_anon(&self, is_first: bool, scope_def_id: DefId) -> bool { is_first && self.tcx - .opt_associated_item(scope_def_id) - .map(|i| i.method_has_self_argument) == Some(true) + .opt_associated_item(scope_def_id) + .map(|i| i.method_has_self_argument) == Some(true) } } diff --git a/src/librustc/infer/lexical_region_resolve/graphviz.rs b/src/librustc/infer/lexical_region_resolve/graphviz.rs index 3f17c9bb020..b55727d2c84 100644 --- a/src/librustc/infer/lexical_region_resolve/graphviz.rs +++ b/src/librustc/infer/lexical_region_resolve/graphviz.rs @@ -112,12 +112,9 @@ pub fn maybe_print_constraints_for<'a, 'gcx, 'tcx>( } }; - match dump_region_data_to(region_rels, ®ion_data.constraints, &output_path) { - Ok(()) => {} - Err(e) => { - let msg = format!("io error dumping region constraints: {}", e); - tcx.sess.err(&msg) - } + if let Err(e) = dump_region_data_to(region_rels, ®ion_data.constraints, &output_path) { + let msg = format!("io error dumping region constraints: {}", e); + tcx.sess.err(&msg) } } @@ -187,12 +184,9 @@ impl<'a, 'gcx, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'gcx, 'tcx> { None => bug!("no node_id found for node: {:?}", n), }; let name = || format!("node_{}", node_id); - match dot::Id::new(name()) { - Ok(id) => id, - Err(_) => { - bug!("failed to create graphviz node identified by {}", name()); - } - } + + dot::Id::new(name()).unwrap_or_else(|_| + bug!("failed to create graphviz node identified by {}", name())) } fn node_label(&self, n: &Node) -> dot::LabelText<'_> { match *n { @@ -204,7 +198,7 @@ impl<'a, 'gcx, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'gcx, 'tcx> { match *e { Edge::Constraint(ref c) => dot::LabelText::label(format!("{:?}", self.map.get(c).unwrap())), - Edge::EnclScope(..) => dot::LabelText::label("(enclosed)".to_string()), + Edge::EnclScope(..) => dot::LabelText::label("(enclosed)".to_owned()), } } } diff --git a/src/librustc/infer/lexical_region_resolve/mod.rs b/src/librustc/infer/lexical_region_resolve/mod.rs index 2046f66f99f..ca49d053210 100644 --- a/src/librustc/infer/lexical_region_resolve/mod.rs +++ b/src/librustc/infer/lexical_region_resolve/mod.rs @@ -147,9 +147,7 @@ impl<'cx, 'gcx, 'tcx> LexicalResolver<'cx, 'gcx, 'tcx> { fn construct_var_data(&self, tcx: TyCtxt<'_, '_, 'tcx>) -> LexicalRegionResolutions<'tcx> { LexicalRegionResolutions { error_region: tcx.types.re_static, - values: (0..self.num_vars()) - .map(|_| VarValue::Value(tcx.types.re_empty)) - .collect(), + values: IndexVec::from_elem_n(VarValue::Value(tcx.types.re_empty), self.num_vars()) } } diff --git a/src/librustc/infer/opaque_types/mod.rs b/src/librustc/infer/opaque_types/mod.rs index e5220aad056..49858972416 100644 --- a/src/librustc/infer/opaque_types/mod.rs +++ b/src/librustc/infer/opaque_types/mod.rs @@ -803,6 +803,7 @@ impl<'a, 'gcx, 'tcx> Instantiator<'a, 'gcx, 'tcx> { ); debug!("instantiate_opaque_types: ty_var={:?}", ty_var); + self.obligations.reserve(bounds.predicates.len()); for predicate in bounds.predicates { // Change the predicate to refer to the type variable, // which will be the concrete type instead of the opaque type. diff --git a/src/librustc/infer/region_constraints/mod.rs b/src/librustc/infer/region_constraints/mod.rs index 95893a71178..87bfbaef54c 100644 --- a/src/librustc/infer/region_constraints/mod.rs +++ b/src/librustc/infer/region_constraints/mod.rs @@ -443,7 +443,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> { assert!(self.undo_log[snapshot.length] == OpenSnapshot); if snapshot.length == 0 { - self.undo_log.truncate(0); + self.undo_log.clear(); } else { (*self.undo_log)[snapshot.length] = CommitedSnapshot; } @@ -661,11 +661,10 @@ impl<'tcx> RegionConstraintCollector<'tcx> { debug!("RegionConstraintCollector: add_verify({:?})", verify); // skip no-op cases known to be satisfied - match verify.bound { - VerifyBound::AllBounds(ref bs) if bs.len() == 0 => { + if let VerifyBound::AllBounds(ref bs) = verify.bound { + if bs.len() == 0 { return; } - _ => {} } let index = self.data.verifys.len(); diff --git a/src/librustc/infer/resolve.rs b/src/librustc/infer/resolve.rs index be13fb9a2a5..0ef97618572 100644 --- a/src/librustc/infer/resolve.rs +++ b/src/librustc/infer/resolve.rs @@ -153,8 +153,8 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for FullTypeResolver<'a, 'gcx, 'tcx> fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { if !t.needs_infer() && !ty::keep_local(&t) { t // micro-optimize -- if there is nothing in this type that this fold affects... - // ^ we need to have the `keep_local` check to un-default - // defaulted tuples. + // ^ we need to have the `keep_local` check to un-default + // defaulted tuples. } else { let t = self.infcx.shallow_resolve(t); match t.sty { diff --git a/src/librustc/infer/type_variable.rs b/src/librustc/infer/type_variable.rs index b1e4fc7c7fc..970b6e096ff 100644 --- a/src/librustc/infer/type_variable.rs +++ b/src/librustc/infer/type_variable.rs @@ -273,11 +273,8 @@ impl<'tcx> TypeVariableTable<'tcx> { pub fn rollback_to(&mut self, s: Snapshot<'tcx>) { debug!("rollback_to{:?}", { for action in self.values.actions_since_snapshot(&s.snapshot) { - match *action { - sv::UndoLog::NewElem(index) => { - debug!("inference variable _#{}t popped", index) - } - _ => { } + if let sv::UndoLog::NewElem(index) = *action { + debug!("inference variable _#{}t popped", index) } } }); 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