Rollup merge of #36396 - athulappadan:Default-docs, r=bluss

Documentation of what Default does for each type

Addresses #36265
I haven't changed the following types due to doubts:

1)src/libstd/ffi/c_str.rs
2)src/libcore/iter/sources.rs
3)src/libcore/hash/mod.rs
4)src/libcore/hash/mod.rs
5)src/librustc/middle/privacy.rs

r? @steveklabnik

8 files changed, 8 insertions, 0 deletions

diff --git a/src/libcollections/binary_heap.rs b/src/libcollections/binary_heap.rs
index 0b923468c74..1fe921543bd 100644
--- a/src/libcollections/binary_heap.rs
+++ b/src/libcollections/binary_heap.rs
@@ -263,6 +263,7 @@ impl<T: Clone> Clone for BinaryHeap<T> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Default for BinaryHeap<T> {
+    /// Creates an empty `BinaryHeap<T>`.
     #[inline]
     fn default() -> BinaryHeap<T> {
         BinaryHeap::new()
diff --git a/src/libcollections/borrow.rs b/src/libcollections/borrow.rs
index 3ad1d082985..700f88dc0f2 100644
--- a/src/libcollections/borrow.rs
+++ b/src/libcollections/borrow.rs
@@ -249,6 +249,7 @@ impl<'a, B: ?Sized> Default for Cow<'a, B>
     where B: ToOwned,
           <B as ToOwned>::Owned: Default
 {
+    /// Creates an owned Cow<'a, B> with the default value for the contained owned value.
     fn default() -> Cow<'a, B> {
         Owned(<B as ToOwned>::Owned::default())
     }
diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index 624083a8eaf..36cb5a1fd9f 100644
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -1667,6 +1667,7 @@ impl<K: Hash, V: Hash> Hash for BTreeMap<K, V> {
 }
 
 impl<K: Ord, V> Default for BTreeMap<K, V> {
+    /// Creates an empty `BTreeMap<K, V>`.
     fn default() -> BTreeMap<K, V> {
         BTreeMap::new()
     }
diff --git a/src/libcollections/btree/set.rs b/src/libcollections/btree/set.rs
index 5d7b00f57c8..fc2a7f82547 100644
--- a/src/libcollections/btree/set.rs
+++ b/src/libcollections/btree/set.rs
@@ -674,6 +674,7 @@ impl<'a, T: 'a + Ord + Copy> Extend<&'a T> for BTreeSet<T> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Ord> Default for BTreeSet<T> {
+    /// Makes an empty `BTreeSet<T>` with a reasonable choice of B.
     fn default() -> BTreeSet<T> {
         BTreeSet::new()
     }
diff --git a/src/libcollections/linked_list.rs b/src/libcollections/linked_list.rs
index 769c5162a45..690c4f4af35 100644
--- a/src/libcollections/linked_list.rs
+++ b/src/libcollections/linked_list.rs
@@ -164,6 +164,7 @@ impl<T> LinkedList<T> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Default for LinkedList<T> {
+    /// Creates an empty `LinkedList<T>`.
     #[inline]
     fn default() -> Self {
         Self::new()
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index 3a304c62929..773e94f1b41 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -1567,6 +1567,7 @@ impl_eq! { Cow<'a, str>, String }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Default for String {
+    /// Creates an empty `String`.
     #[inline]
     fn default() -> String {
         String::new()
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index 7388e883434..f8b4a92df2c 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -1652,6 +1652,7 @@ impl<T> Drop for Vec<T> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Default for Vec<T> {
+    /// Creates an empty `Vec<T>`.
     fn default() -> Vec<T> {
         Vec::new()
     }
diff --git a/src/libcollections/vec_deque.rs b/src/libcollections/vec_deque.rs
index 96624f121b2..2e561dabb47 100644
--- a/src/libcollections/vec_deque.rs
+++ b/src/libcollections/vec_deque.rs
@@ -84,6 +84,7 @@ impl<T> Drop for VecDeque<T> {
 
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Default for VecDeque<T> {
+    /// Creates an empty `VecDeque<T>`.
     #[inline]
     fn default() -> VecDeque<T> {
         VecDeque::new()