specialize: remove Boxes used by Children::insert
diff --git a/src/librustc/traits/specialize/specialization_graph.rs b/src/librustc/traits/specialize/specialization_graph.rs
index 22221e0..b0ca2f6 100644
--- a/src/librustc/traits/specialize/specialization_graph.rs
+++ b/src/librustc/traits/specialize/specialization_graph.rs
@@ -132,10 +132,12 @@
simplified_self,
);
- for possible_sibling in match simplified_self {
- Some(sty) => self.filtered(sty),
- None => self.iter(),
- } {
+ let possible_siblings = match simplified_self {
+ Some(sty) => PotentialSiblings::Filtered(self.filtered(sty)),
+ None => PotentialSiblings::Unfiltered(self.iter()),
+ };
+
+ for possible_sibling in possible_siblings {
debug!(
"insert: impl_def_id={:?}, simplified_self={:?}, possible_sibling={:?}",
impl_def_id,
@@ -222,14 +224,37 @@
Ok(Inserted::BecameNewSibling(last_lint))
}
- fn iter(&mut self) -> Box<dyn Iterator<Item = DefId> + '_> {
+ fn iter(&mut self) -> impl Iterator<Item = DefId> + '_ {
let nonblanket = self.nonblanket_impls.iter_mut().flat_map(|(_, v)| v.iter());
- Box::new(self.blanket_impls.iter().chain(nonblanket).cloned())
+ self.blanket_impls.iter().chain(nonblanket).cloned()
}
- fn filtered(&mut self, sty: SimplifiedType) -> Box<dyn Iterator<Item = DefId> + '_> {
+ fn filtered(&mut self, sty: SimplifiedType) -> impl Iterator<Item = DefId> + '_ {
let nonblanket = self.nonblanket_impls.entry(sty).or_default().iter();
- Box::new(self.blanket_impls.iter().chain(nonblanket).cloned())
+ self.blanket_impls.iter().chain(nonblanket).cloned()
+ }
+}
+
+// A custom iterator used by Children::insert
+enum PotentialSiblings<I, J>
+ where I: Iterator<Item = DefId>,
+ J: Iterator<Item = DefId>
+{
+ Unfiltered(I),
+ Filtered(J)
+}
+
+impl<I, J> Iterator for PotentialSiblings<I, J>
+ where I: Iterator<Item = DefId>,
+ J: Iterator<Item = DefId>
+{
+ type Item = DefId;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ match *self {
+ PotentialSiblings::Unfiltered(ref mut iter) => iter.next(),
+ PotentialSiblings::Filtered(ref mut iter) => iter.next()
+ }
}
}
