reduce borrowing and (de)referencing around match patterns (clippy::match_ref_pats)

This commit is contained in:
Matthias Krüger 2021-01-02 20:09:17 +01:00
parent 90ccf4f5ad
commit 8a90626a46
28 changed files with 89 additions and 91 deletions

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@ -433,9 +433,9 @@ pub enum WherePredicate {
impl WherePredicate {
pub fn span(&self) -> Span {
match self {
&WherePredicate::BoundPredicate(ref p) => p.span,
&WherePredicate::RegionPredicate(ref p) => p.span,
&WherePredicate::EqPredicate(ref p) => p.span,
WherePredicate::BoundPredicate(p) => p.span,
WherePredicate::RegionPredicate(p) => p.span,
WherePredicate::EqPredicate(p) => p.span,
}
}
}

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@ -1212,11 +1212,11 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
}
fn visit_pat(&mut self, pat: &'a Pat) {
match pat.kind {
PatKind::Lit(ref expr) => {
match &pat.kind {
PatKind::Lit(expr) => {
self.check_expr_within_pat(expr, false);
}
PatKind::Range(ref start, ref end, _) => {
PatKind::Range(start, end, _) => {
if let Some(expr) = start {
self.check_expr_within_pat(expr, true);
}

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@ -48,8 +48,8 @@ pub fn expand_deriving_hash(
}
fn hash_substructure(cx: &mut ExtCtxt<'_>, trait_span: Span, substr: &Substructure<'_>) -> P<Expr> {
let state_expr = match &substr.nonself_args {
&[o_f] => o_f,
let state_expr = match substr.nonself_args {
[o_f] => o_f,
_ => cx.span_bug(trait_span, "incorrect number of arguments in `derive(Hash)`"),
};
let call_hash = |span, thing_expr| {
@ -64,9 +64,9 @@ fn hash_substructure(cx: &mut ExtCtxt<'_>, trait_span: Span, substr: &Substructu
};
let mut stmts = Vec::new();
let fields = match *substr.fields {
Struct(_, ref fs) | EnumMatching(_, 1, .., ref fs) => fs,
EnumMatching(.., ref fs) => {
let fields = match substr.fields {
Struct(_, fs) | EnumMatching(_, 1, .., fs) => fs,
EnumMatching(.., fs) => {
let variant_value = deriving::call_intrinsic(
cx,
trait_span,

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@ -378,9 +378,9 @@ impl GenericBound<'_> {
pub fn span(&self) -> Span {
match self {
&GenericBound::Trait(ref t, ..) => t.span,
&GenericBound::LangItemTrait(_, span, ..) => span,
&GenericBound::Outlives(ref l) => l.span,
GenericBound::Trait(t, ..) => t.span,
GenericBound::LangItemTrait(_, span, ..) => *span,
GenericBound::Outlives(l) => l.span,
}
}
}
@ -538,9 +538,9 @@ pub enum WherePredicate<'hir> {
impl WherePredicate<'_> {
pub fn span(&self) -> Span {
match self {
&WherePredicate::BoundPredicate(ref p) => p.span,
&WherePredicate::RegionPredicate(ref p) => p.span,
&WherePredicate::EqPredicate(ref p) => p.span,
WherePredicate::BoundPredicate(p) => p.span,
WherePredicate::RegionPredicate(p) => p.span,
WherePredicate::EqPredicate(p) => p.span,
}
}
}

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@ -896,8 +896,8 @@ pub fn walk_where_predicate<'v, V: Visitor<'v>>(
visitor: &mut V,
predicate: &'v WherePredicate<'v>,
) {
match predicate {
&WherePredicate::BoundPredicate(WhereBoundPredicate {
match *predicate {
WherePredicate::BoundPredicate(WhereBoundPredicate {
ref bounded_ty,
bounds,
bound_generic_params,
@ -907,11 +907,11 @@ pub fn walk_where_predicate<'v, V: Visitor<'v>>(
walk_list!(visitor, visit_param_bound, bounds);
walk_list!(visitor, visit_generic_param, bound_generic_params);
}
&WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
visitor.visit_lifetime(lifetime);
walk_list!(visitor, visit_param_bound, bounds);
}
&WherePredicate::EqPredicate(WhereEqPredicate {
WherePredicate::EqPredicate(WhereEqPredicate {
hir_id, ref lhs_ty, ref rhs_ty, ..
}) => {
visitor.visit_id(hir_id);

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@ -2233,19 +2233,19 @@ impl<'a> State<'a> {
}
match predicate {
&hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
ref bound_generic_params,
ref bounded_ty,
hir::WherePredicate::BoundPredicate(hir::WhereBoundPredicate {
bound_generic_params,
bounded_ty,
bounds,
..
}) => {
self.print_formal_generic_params(bound_generic_params);
self.print_type(&bounded_ty);
self.print_bounds(":", bounds);
self.print_bounds(":", *bounds);
}
&hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate {
ref lifetime,
ref bounds,
hir::WherePredicate::RegionPredicate(hir::WhereRegionPredicate {
lifetime,
bounds,
..
}) => {
self.print_lifetime(lifetime);
@ -2264,10 +2264,8 @@ impl<'a> State<'a> {
}
}
}
&hir::WherePredicate::EqPredicate(hir::WhereEqPredicate {
ref lhs_ty,
ref rhs_ty,
..
hir::WherePredicate::EqPredicate(hir::WhereEqPredicate {
lhs_ty, rhs_ty, ..
}) => {
self.print_type(lhs_ty);
self.s.space();

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@ -310,13 +310,13 @@ fn filter_nodes<'q>(
sources: &Option<FxHashSet<&'q DepNode>>,
targets: &Option<FxHashSet<&'q DepNode>>,
) -> FxHashSet<&'q DepNode> {
if let &Some(ref sources) = sources {
if let &Some(ref targets) = targets {
if let Some(sources) = sources {
if let Some(targets) = targets {
walk_between(query, sources, targets)
} else {
walk_nodes(query, sources, OUTGOING)
}
} else if let &Some(ref targets) = targets {
} else if let Some(targets) = targets {
walk_nodes(query, targets, INCOMING)
} else {
query.nodes().into_iter().collect()

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@ -915,7 +915,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
self.highlight_outer(&mut t1_out, &mut t2_out, path, sub, i, &other_ty);
return Some(());
}
if let &ty::Adt(def, _) = ta.kind() {
if let ty::Adt(def, _) = ta.kind() {
let path_ = self.tcx.def_path_str(def.did);
if path_ == other_path {
self.highlight_outer(&mut t1_out, &mut t2_out, path, sub, i, &other_ty);

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@ -938,8 +938,8 @@ impl EarlyLintPass for DeprecatedAttr {
if attr.ident().map(|ident| ident.name) == Some(n) {
if let &AttributeGate::Gated(
Stability::Deprecated(link, suggestion),
ref name,
ref reason,
name,
reason,
_,
) = g
{

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@ -397,7 +397,7 @@ impl<'tcx> LateLintPass<'tcx> for NonSnakeCase {
}
fn check_pat(&mut self, cx: &LateContext<'_>, p: &hir::Pat<'_>) {
if let &PatKind::Binding(_, hid, ident, _) = &p.kind {
if let PatKind::Binding(_, hid, ident, _) = p.kind {
if let hir::Node::Pat(parent_pat) = cx.tcx.hir().get(cx.tcx.hir().get_parent_node(hid))
{
if let PatKind::Struct(_, field_pats, _) = &parent_pat.kind {

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@ -862,11 +862,11 @@ impl EarlyLintPass for UnusedParens {
}
fn check_ty(&mut self, cx: &EarlyContext<'_>, ty: &ast::Ty) {
if let &ast::TyKind::Paren(ref r) = &ty.kind {
if let ast::TyKind::Paren(r) = &ty.kind {
match &r.kind {
&ast::TyKind::TraitObject(..) => {}
&ast::TyKind::ImplTrait(_, ref bounds) if bounds.len() > 1 => {}
&ast::TyKind::Array(_, ref len) => {
ast::TyKind::TraitObject(..) => {}
ast::TyKind::ImplTrait(_, bounds) if bounds.len() > 1 => {}
ast::TyKind::Array(_, len) => {
self.check_unused_delims_expr(
cx,
&len.value,

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@ -192,13 +192,13 @@ impl Collector<'tcx> {
fn process_command_line(&mut self) {
// First, check for errors
let mut renames = FxHashSet::default();
for &(ref name, ref new_name, _) in &self.tcx.sess.opts.libs {
if let &Some(ref new_name) = new_name {
for (name, new_name, _) in &self.tcx.sess.opts.libs {
if let Some(ref new_name) = new_name {
let any_duplicate = self
.libs
.iter()
.filter_map(|lib| lib.name.as_ref())
.any(|n| n.as_str() == *name);
.any(|n| &n.as_str() == name);
if new_name.is_empty() {
self.tcx.sess.err(&format!(
"an empty renaming target was specified for library `{}`",
@ -240,7 +240,7 @@ impl Collector<'tcx> {
if kind != NativeLibKind::Unspecified {
lib.kind = kind;
}
if let &Some(ref new_name) = new_name {
if let Some(new_name) = new_name {
lib.name = Some(Symbol::intern(new_name));
}
return true;

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@ -245,8 +245,8 @@ pub fn suggest_constraining_type_param(
}
}
match &param_spans[..] {
&[&param_span] => suggest_restrict(param_span.shrink_to_hi()),
match param_spans[..] {
[&param_span] => suggest_restrict(param_span.shrink_to_hi()),
_ => {
err.span_suggestion_verbose(
generics.where_clause.tail_span_for_suggestion(),

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@ -302,7 +302,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
.find_map(|p| self.is_upvar_field_projection(p));
let deref_base = match deref_target_place.projection.as_ref() {
&[ref proj_base @ .., ProjectionElem::Deref] => {
[proj_base @ .., ProjectionElem::Deref] => {
PlaceRef { local: deref_target_place.local, projection: &proj_base }
}
_ => bug!("deref_target_place is not a deref projection"),

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@ -1855,8 +1855,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
self.assert_iscleanup(body, block_data, unwind, true);
}
}
TerminatorKind::InlineAsm { ref destination, .. } => {
if let &Some(target) = destination {
TerminatorKind::InlineAsm { destination, .. } => {
if let Some(target) = destination {
self.assert_iscleanup(body, block_data, target, is_cleanup);
}
}

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@ -149,7 +149,7 @@ impl<'tcx> Visitor<'tcx> for CheckParameters<'tcx> {
fn check_asm<'tcx>(tcx: TyCtxt<'tcx>, hir_id: HirId, body: &'tcx hir::Body<'tcx>, fn_span: Span) {
let mut this = CheckInlineAssembly { tcx, items: Vec::new() };
this.visit_body(body);
if let &[(ItemKind::Asm, _)] = &this.items[..] {
if let [(ItemKind::Asm, _)] = this.items[..] {
// Ok.
} else {
tcx.struct_span_lint_hir(UNSUPPORTED_NAKED_FUNCTIONS, hir_id, fn_span, |lint| {

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@ -582,7 +582,7 @@ impl<'tcx> DumpVisitor<'tcx> {
}
ref v => {
let mut value = format!("{}::{}", enum_data.name, name);
if let &hir::VariantData::Tuple(ref fields, _) = v {
if let hir::VariantData::Tuple(fields, _) = v {
value.push('(');
value.push_str(
&fields
@ -653,7 +653,7 @@ impl<'tcx> DumpVisitor<'tcx> {
let map = &self.tcx.hir();
self.nest_typeck_results(map.local_def_id(item.hir_id), |v| {
v.visit_ty(&typ);
if let &Some(ref trait_ref) = trait_ref {
if let Some(trait_ref) = trait_ref {
v.process_path(trait_ref.hir_ref_id, &hir::QPath::Resolved(None, &trait_ref.path));
}
v.process_generic_params(generics, "", item.hir_id);
@ -1082,7 +1082,7 @@ impl<'tcx> DumpVisitor<'tcx> {
);
}
if let &Some(ref default_ty) = default_ty {
if let Some(default_ty) = default_ty {
self.visit_ty(default_ty)
}
}

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@ -305,8 +305,8 @@ impl AutoTraitFinder<'tcx> {
infcx.resolve_vars_if_possible(Obligation::new(dummy_cause.clone(), new_env, pred));
let result = select.select(&obligation);
match &result {
&Ok(Some(ref impl_source)) => {
match result {
Ok(Some(ref impl_source)) => {
// If we see an explicit negative impl (e.g., `impl !Send for MyStruct`),
// we immediately bail out, since it's impossible for us to continue.
@ -339,8 +339,8 @@ impl AutoTraitFinder<'tcx> {
return None;
}
}
&Ok(None) => {}
&Err(SelectionError::Unimplemented) => {
Ok(None) => {}
Err(SelectionError::Unimplemented) => {
if self.is_param_no_infer(pred.skip_binder().trait_ref.substs) {
already_visited.remove(&pred);
self.add_user_pred(
@ -863,7 +863,7 @@ impl<'a, 'tcx> TypeFolder<'tcx> for RegionReplacer<'a, 'tcx> {
fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
(match r {
&ty::ReVar(vid) => self.vid_to_region.get(&vid).cloned(),
ty::ReVar(vid) => self.vid_to_region.get(vid).cloned(),
_ => None,
})
.unwrap_or_else(|| r.super_fold_with(self))

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@ -1368,7 +1368,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
code: &ObligationCauseCode<'tcx>,
) -> Option<(String, Option<Span>)> {
match code {
&ObligationCauseCode::BuiltinDerivedObligation(ref data) => {
ObligationCauseCode::BuiltinDerivedObligation(data) => {
let parent_trait_ref = self.resolve_vars_if_possible(data.parent_trait_ref);
match self.get_parent_trait_ref(&data.parent_code) {
Some(t) => Some(t),

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@ -69,16 +69,16 @@ impl IntercrateAmbiguityCause {
pub fn intercrate_ambiguity_hint(&self) -> String {
match self {
&IntercrateAmbiguityCause::DownstreamCrate { ref trait_desc, ref self_desc } => {
let self_desc = if let &Some(ref ty) = self_desc {
IntercrateAmbiguityCause::DownstreamCrate { trait_desc, self_desc } => {
let self_desc = if let Some(ty) = self_desc {
format!(" for type `{}`", ty)
} else {
String::new()
};
format!("downstream crates may implement trait `{}`{}", trait_desc, self_desc)
}
&IntercrateAmbiguityCause::UpstreamCrateUpdate { ref trait_desc, ref self_desc } => {
let self_desc = if let &Some(ref ty) = self_desc {
IntercrateAmbiguityCause::UpstreamCrateUpdate { trait_desc, self_desc } => {
let self_desc = if let Some(ty) = self_desc {
format!(" for type `{}`", ty)
} else {
String::new()
@ -89,7 +89,7 @@ impl IntercrateAmbiguityCause {
trait_desc, self_desc
)
}
&IntercrateAmbiguityCause::ReservationImpl { ref message } => message.clone(),
IntercrateAmbiguityCause::ReservationImpl { message } => message.clone(),
}
}
}

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@ -770,7 +770,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
// Try to find an unbound in bounds.
let mut unbound = None;
for ab in ast_bounds {
if let &hir::GenericBound::Trait(ref ptr, hir::TraitBoundModifier::Maybe) = ab {
if let hir::GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = ab {
if unbound.is_none() {
unbound = Some(&ptr.trait_ref);
} else {

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@ -290,16 +290,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
ty::FnPtr(sig) => (sig, None),
ref t => {
let mut unit_variant = None;
if let &ty::Adt(adt_def, ..) = t {
if let ty::Adt(adt_def, ..) = t {
if adt_def.is_enum() {
if let hir::ExprKind::Call(ref expr, _) = call_expr.kind {
if let hir::ExprKind::Call(expr, _) = call_expr.kind {
unit_variant =
self.tcx.sess.source_map().span_to_snippet(expr.span).ok();
}
}
}
if let hir::ExprKind::Call(ref callee, _) = call_expr.kind {
if let hir::ExprKind::Call(callee, _) = call_expr.kind {
let mut err = type_error_struct!(
self.tcx.sess,
callee.span,

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@ -926,11 +926,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
false
}
};
if is_capturing_closure(&prev_ty.kind()) || is_capturing_closure(&new_ty.kind()) {
if is_capturing_closure(prev_ty.kind()) || is_capturing_closure(new_ty.kind()) {
(None, None)
} else {
match (&prev_ty.kind(), &new_ty.kind()) {
(&ty::FnDef(..), &ty::FnDef(..)) => {
match (prev_ty.kind(), new_ty.kind()) {
(ty::FnDef(..), ty::FnDef(..)) => {
// Don't reify if the function types have a LUB, i.e., they
// are the same function and their parameters have a LUB.
match self
@ -943,21 +943,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
}
}
(&ty::Closure(_, substs), &ty::FnDef(..)) => {
(ty::Closure(_, substs), ty::FnDef(..)) => {
let b_sig = new_ty.fn_sig(self.tcx);
let a_sig = self
.tcx
.signature_unclosure(substs.as_closure().sig(), b_sig.unsafety());
(Some(a_sig), Some(b_sig))
}
(&ty::FnDef(..), &ty::Closure(_, substs)) => {
(ty::FnDef(..), ty::Closure(_, substs)) => {
let a_sig = prev_ty.fn_sig(self.tcx);
let b_sig = self
.tcx
.signature_unclosure(substs.as_closure().sig(), a_sig.unsafety());
(Some(a_sig), Some(b_sig))
}
(&ty::Closure(_, substs_a), &ty::Closure(_, substs_b)) => (
(ty::Closure(_, substs_a), ty::Closure(_, substs_b)) => (
Some(self.tcx.signature_unclosure(
substs_a.as_closure().sig(),
hir::Unsafety::Normal,

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@ -1125,7 +1125,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
fields,
base_expr.is_none(),
);
if let &Some(ref base_expr) = base_expr {
if let Some(base_expr) = base_expr {
// If check_expr_struct_fields hit an error, do not attempt to populate
// the fields with the base_expr. This could cause us to hit errors later
// when certain fields are assumed to exist that in fact do not.
@ -1182,8 +1182,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// re-link the regions that EIfEO can erase.
self.demand_eqtype(span, adt_ty_hint, adt_ty);
let (substs, adt_kind, kind_name) = match &adt_ty.kind() {
&ty::Adt(adt, substs) => (substs, adt.adt_kind(), adt.variant_descr()),
let (substs, adt_kind, kind_name) = match adt_ty.kind() {
ty::Adt(adt, substs) => (substs, adt.adt_kind(), adt.variant_descr()),
_ => span_bug!(span, "non-ADT passed to check_expr_struct_fields"),
};

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@ -333,7 +333,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
ExprKind::Path(ref qpath) => {
// local binding
if let &QPath::Resolved(_, ref path) = &qpath {
if let QPath::Resolved(_, path) = qpath {
if let hir::def::Res::Local(hir_id) = path.res {
let span = tcx.hir().span(hir_id);
let snippet = tcx.sess.source_map().span_to_snippet(span);

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@ -1920,7 +1920,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
let where_clause = &ast_generics.where_clause;
for predicate in where_clause.predicates {
match predicate {
&hir::WherePredicate::BoundPredicate(ref bound_pred) => {
hir::WherePredicate::BoundPredicate(bound_pred) => {
let ty = icx.to_ty(&bound_pred.bounded_ty);
// Keep the type around in a dummy predicate, in case of no bounds.
@ -1949,7 +1949,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
for bound in bound_pred.bounds.iter() {
match bound {
&hir::GenericBound::Trait(ref poly_trait_ref, modifier) => {
hir::GenericBound::Trait(poly_trait_ref, modifier) => {
let constness = match modifier {
hir::TraitBoundModifier::MaybeConst => hir::Constness::NotConst,
hir::TraitBoundModifier::None => constness,
@ -1959,7 +1959,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
let mut bounds = Bounds::default();
let _ = AstConv::instantiate_poly_trait_ref(
&icx,
poly_trait_ref,
&poly_trait_ref,
constness,
ty,
&mut bounds,
@ -1981,7 +1981,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
predicates.extend(bounds.predicates(tcx, ty));
}
&hir::GenericBound::Outlives(ref lifetime) => {
hir::GenericBound::Outlives(lifetime) => {
let region = AstConv::ast_region_to_region(&icx, lifetime, None);
predicates.insert((
ty::Binder::bind(ty::PredicateAtom::TypeOutlives(
@ -1995,7 +1995,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
}
}
&hir::WherePredicate::RegionPredicate(ref region_pred) => {
hir::WherePredicate::RegionPredicate(region_pred) => {
let r1 = AstConv::ast_region_to_region(&icx, &region_pred.lifetime, None);
predicates.extend(region_pred.bounds.iter().map(|bound| {
let (r2, span) = match bound {
@ -2011,7 +2011,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
}))
}
&hir::WherePredicate::EqPredicate(..) => {
hir::WherePredicate::EqPredicate(..) => {
// FIXME(#20041)
}
}

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@ -351,8 +351,8 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
if let Some(data) = ty_to_fn.get(&ty) {
let (poly_trait, output) =
(data.0.as_ref().expect("as_ref failed").clone(), data.1.as_ref().cloned());
let new_ty = match &poly_trait.trait_ {
&Type::ResolvedPath {
let new_ty = match poly_trait.trait_ {
Type::ResolvedPath {
ref path,
ref param_names,
ref did,

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@ -179,12 +179,12 @@ crate fn get_real_types(
if arg.is_full_generic() {
let arg_s = Symbol::intern(&arg.print().to_string());
if let Some(where_pred) = generics.where_predicates.iter().find(|g| match g {
&WherePredicate::BoundPredicate { ref ty, .. } => ty.def_id() == arg.def_id(),
WherePredicate::BoundPredicate { ty, .. } => ty.def_id() == arg.def_id(),
_ => false,
}) {
let bounds = where_pred.get_bounds().unwrap_or_else(|| &[]);
for bound in bounds.iter() {
if let GenericBound::TraitBound(ref poly_trait, _) = *bound {
if let GenericBound::TraitBound(poly_trait, _) = bound {
for x in poly_trait.generic_params.iter() {
if !x.is_type() {
continue;