impl Default for Hash{Map,Set} iterators that don't already have it

Author: clarfonthey

library/std/src/collections/hash/map.rs

@@ -1438,6 +1438,14 @@ impl<K, V> Clone for Iter<'_, K, V> {
 }
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforIter<'_,K,V>{
+#[inline]
+fndefault() -> Self{
+Iter{base:Default::default()}
+}
+}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl<K:Debug,V:Debug> fmt::DebugforIter<'_,K,V>{
 fnfmt(&self,f:&mut fmt::Formatter<'_>) -> fmt::Result{
@@ -1476,6 +1484,14 @@ impl<'a, K, V> IterMut<'a, K, V> {
 }
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforIterMut<'_,K,V>{
+#[inline]
+fndefault() -> Self{
+IterMut{base:Default::default()}
+}
+}
+
 /// An owning iterator over the entries of a `HashMap`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`HashMap`]
@@ -1506,6 +1522,14 @@ impl<K, V> IntoIter<K, V> {
 }
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforIntoIter<K,V>{
+#[inline]
+fndefault() -> Self{
+IntoIter{base:Default::default()}
+}
+}
+
 /// An iterator over the keys of a `HashMap`.
 ///
 /// This `struct` is created by the [`keys`] method on [`HashMap`]. See its
@@ -1538,6 +1562,14 @@ impl<K, V> Clone for Keys<'_, K, V> {
 }
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforKeys<'_,K,V>{
+#[inline]
+fndefault() -> Self{
+Keys{inner:Default::default()}
+}
+}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl<K:Debug,V> fmt::DebugforKeys<'_,K,V>{
 fnfmt(&self,f:&mut fmt::Formatter<'_>) -> fmt::Result{
@@ -1577,6 +1609,14 @@ impl<K, V> Clone for Values<'_, K, V> {
 }
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforValues<'_,K,V>{
+#[inline]
+fndefault() -> Self{
+Values{inner:Default::default()}
+}
+}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl<K,V:Debug> fmt::DebugforValues<'_,K,V>{
 fnfmt(&self,f:&mut fmt::Formatter<'_>) -> fmt::Result{
@@ -1665,6 +1705,14 @@ pub struct ValuesMut<'a, K: 'a, V: 'a> {
 inner:IterMut<'a,K,V>,
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforValuesMut<'_,K,V>{
+#[inline]
+fndefault() -> Self{
+ValuesMut{inner:Default::default()}
+}
+}
+
 /// An owning iterator over the keys of a `HashMap`.
 ///
 /// This `struct` is created by the [`into_keys`] method on [`HashMap`].
@@ -1687,6 +1735,14 @@ pub struct IntoKeys<K, V> {
 inner:IntoIter<K,V>,
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforIntoKeys<K,V>{
+#[inline]
+fndefault() -> Self{
+IntoKeys{inner:Default::default()}
+}
+}
+
 /// An owning iterator over the values of a `HashMap`.
 ///
 /// This `struct` is created by the [`into_values`] method on [`HashMap`].
@@ -1709,6 +1765,14 @@ pub struct IntoValues<K, V> {
 inner:IntoIter<K,V>,
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K,V>DefaultforIntoValues<K,V>{
+#[inline]
+fndefault() -> Self{
+IntoValues{inner:Default::default()}
+}
+}
+
 /// A builder for computing where in a HashMap a key-value pair would be stored.
 ///
 /// See the [`HashMap::raw_entry_mut`] docs for usage examples.

library/std/src/collections/hash/set.rs

@@ -1244,6 +1244,14 @@ pub struct Iter<'a, K: 'a> {
 base: base::Iter<'a,K>,
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K>DefaultforIter<'_,K>{
+#[inline]
+fndefault() -> Self{
+Iter{base:Default::default()}
+}
+}
+
 /// An owning iterator over the items of a `HashSet`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`HashSet`]
@@ -1265,6 +1273,14 @@ pub struct IntoIter<K> {
 base: base::IntoIter<K>,
 }
 
+#[stable(feature = "default_iters_hash", since = "CURRENT_RUSTC_VERSION")]
+impl<K>DefaultforIntoIter<K>{
+#[inline]
+fndefault() -> Self{
+IntoIter{base:Default::default()}
+}
+}
+
 /// A draining iterator over the items of a `HashSet`.
 ///
 /// This `struct` is created by the [`drain`] method on [`HashSet`].