Auto merge of #39002 - GuillaumeGomez:debug_libcollections, r=aturon

Add Debug implementations for libcollection structs

Part of #31869.

10 files changed, 257 insertions, 0 deletions

diff --git a/src/libcollections/binary_heap.rs b/src/libcollections/binary_heap.rs
index 23e0295ba54..a5a2f70492d 100644
--- a/src/libcollections/binary_heap.rs
+++ b/src/libcollections/binary_heap.rs
@@ -228,6 +228,15 @@ pub struct PeekMut<'a, T: 'a + Ord> {
     sift: bool,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: Ord + fmt::Debug> fmt::Debug for PeekMut<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("PeekMut")
+         .field(&self.heap.data[0])
+         .finish()
+    }
+}
+
 #[stable(feature = "binary_heap_peek_mut", since = "1.12.0")]
 impl<'a, T: Ord> Drop for PeekMut<'a, T> {
     fn drop(&mut self) {
@@ -968,6 +977,15 @@ pub struct Iter<'a, T: 'a> {
     iter: slice::Iter<'a, T>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Iter<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Iter")
+         .field(&self.iter.as_slice())
+         .finish()
+    }
+}
+
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> Clone for Iter<'a, T> {
@@ -1016,6 +1034,15 @@ pub struct IntoIter<T> {
     iter: vec::IntoIter<T>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("IntoIter")
+         .field(&self.iter.as_slice())
+         .finish()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Iterator for IntoIter<T> {
     type Item = T;
@@ -1051,6 +1078,7 @@ impl<T> FusedIterator for IntoIter<T> {}
 
 /// An iterator that drains a `BinaryHeap`.
 #[stable(feature = "drain", since = "1.6.0")]
+#[derive(Debug)]
 pub struct Drain<'a, T: 'a> {
     iter: vec::Drain<'a, T>,
 }
@@ -1203,6 +1231,17 @@ where T: Clone + Ord {
 #[unstable(feature = "collection_placement",
            reason = "placement protocol is subject to change",
            issue = "30172")]
+impl<'a, T: Clone + Ord + fmt::Debug> fmt::Debug for BinaryHeapPlace<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("BinaryHeapPlace")
+         .field(&self.place)
+         .finish()
+    }
+}
+
+#[unstable(feature = "collection_placement",
+           reason = "placement protocol is subject to change",
+           issue = "30172")]
 impl<'a, T: 'a> Placer<T> for &'a mut BinaryHeap<T>
 where T: Clone + Ord {
     type Place = BinaryHeapPlace<'a, T>;
diff --git a/src/libcollections/btree/map.rs b/src/libcollections/btree/map.rs
index 4755f8a4c55..e1fabe2cc49 100644
--- a/src/libcollections/btree/map.rs
+++ b/src/libcollections/btree/map.rs
@@ -270,8 +270,16 @@ pub struct Iter<'a, K: 'a, V: 'a> {
     length: usize,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Iter<'a, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
 /// A mutable iterator over a BTreeMap's entries.
 #[stable(feature = "rust1", since = "1.0.0")]
+#[derive(Debug)]
 pub struct IterMut<'a, K: 'a, V: 'a> {
     range: RangeMut<'a, K, V>,
     length: usize,
@@ -285,20 +293,46 @@ pub struct IntoIter<K, V> {
     length: usize,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IntoIter<K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let range = Range {
+            front: self.front.reborrow(),
+            back: self.back.reborrow(),
+        };
+        f.debug_list().entries(range).finish()
+    }
+}
+
 /// An iterator over a BTreeMap's keys.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Keys<'a, K: 'a, V: 'a> {
     inner: Iter<'a, K, V>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Keys<'a, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_list().entries(self.inner.clone()).finish()
+    }
+}
+
 /// An iterator over a BTreeMap's values.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Values<'a, K: 'a, V: 'a> {
     inner: Iter<'a, K, V>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Values<'a, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_list().entries(self.inner.clone()).finish()
+    }
+}
+
 /// A mutable iterator over a BTreeMap's values.
 #[stable(feature = "map_values_mut", since = "1.10.0")]
+#[derive(Debug)]
 pub struct ValuesMut<'a, K: 'a, V: 'a> {
     inner: IterMut<'a, K, V>,
 }
@@ -309,6 +343,13 @@ pub struct Range<'a, K: 'a, V: 'a> {
     back: Handle<NodeRef<marker::Immut<'a>, K, V, marker::Leaf>, marker::Edge>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for Range<'a, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_list().entries(self.clone()).finish()
+    }
+}
+
 /// A mutable iterator over a sub-range of BTreeMap's entries.
 pub struct RangeMut<'a, K: 'a, V: 'a> {
     front: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>,
@@ -318,6 +359,17 @@ pub struct RangeMut<'a, K: 'a, V: 'a> {
     _marker: PhantomData<&'a mut (K, V)>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, K: 'a + fmt::Debug, V: 'a + fmt::Debug> fmt::Debug for RangeMut<'a, K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let range = Range {
+            front: self.front.reborrow(),
+            back: self.back.reborrow(),
+        };
+        f.debug_list().entries(range).finish()
+    }
+}
+
 /// A view into a single entry in a map, which may either be vacant or occupied.
 /// This enum is constructed from the [`entry`] method on [`BTreeMap`].
 ///
diff --git a/src/libcollections/btree/set.rs b/src/libcollections/btree/set.rs
index f006ba95371..bfffa0b8efa 100644
--- a/src/libcollections/btree/set.rs
+++ b/src/libcollections/btree/set.rs
@@ -85,6 +85,15 @@ pub struct Iter<'a, T: 'a> {
     iter: Keys<'a, T, ()>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Iter<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Iter")
+         .field(&self.iter.clone())
+         .finish()
+    }
+}
+
 /// An owning iterator over a `BTreeSet`'s items.
 ///
 /// This structure is created by the `into_iter` method on [`BTreeSet`]
@@ -92,6 +101,7 @@ pub struct Iter<'a, T: 'a> {
 ///
 /// [`BTreeSet`]: struct.BTreeSet.html
 #[stable(feature = "rust1", since = "1.0.0")]
+#[derive(Debug)]
 pub struct IntoIter<T> {
     iter: ::btree_map::IntoIter<T, ()>,
 }
@@ -102,6 +112,7 @@ pub struct IntoIter<T> {
 ///
 /// [`BTreeSet`]: struct.BTreeSet.html
 /// [`range`]: struct.BTreeSet.html#method.range
+#[derive(Debug)]
 pub struct Range<'a, T: 'a> {
     iter: ::btree_map::Range<'a, T, ()>,
 }
@@ -118,6 +129,15 @@ pub struct Difference<'a, T: 'a> {
     b: Peekable<Iter<'a, T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Difference<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Difference")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 /// A lazy iterator producing elements in the set symmetric difference (in-order).
 ///
 /// This structure is created by the [`symmetric_difference`] method on
@@ -131,6 +151,15 @@ pub struct SymmetricDifference<'a, T: 'a> {
     b: Peekable<Iter<'a, T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for SymmetricDifference<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("SymmetricDifference")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 /// A lazy iterator producing elements in the set intersection (in-order).
 ///
 /// This structure is created by the [`intersection`] method on [`BTreeSet`].
@@ -143,6 +172,15 @@ pub struct Intersection<'a, T: 'a> {
     b: Peekable<Iter<'a, T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Intersection<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Intersection")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 /// A lazy iterator producing elements in the set union (in-order).
 ///
 /// This structure is created by the [`union`] method on [`BTreeSet`].
@@ -155,6 +193,15 @@ pub struct Union<'a, T: 'a> {
     b: Peekable<Iter<'a, T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Union<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Union")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 impl<T: Ord> BTreeSet<T> {
     /// Makes a new `BTreeSet` with a reasonable choice of B.
     ///
diff --git a/src/libcollections/enum_set.rs b/src/libcollections/enum_set.rs
index 78b61079777..602e874aaee 100644
--- a/src/libcollections/enum_set.rs
+++ b/src/libcollections/enum_set.rs
@@ -222,6 +222,14 @@ pub struct Iter<E> {
     marker: marker::PhantomData<E>,
 }
 
+impl<E: fmt::Debug> fmt::Debug for Iter<E> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Iter")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 impl<E> Clone for Iter<E> {
     fn clone(&self) -> Iter<E> {
diff --git a/src/libcollections/lib.rs b/src/libcollections/lib.rs
index 39de87c0840..53d5466e12b 100644
--- a/src/libcollections/lib.rs
+++ b/src/libcollections/lib.rs
@@ -28,6 +28,7 @@
 
 #![cfg_attr(test, allow(deprecated))] // rand
 #![deny(warnings)]
+#![deny(missing_debug_implementations)]
 
 #![feature(alloc)]
 #![feature(allow_internal_unstable)]
diff --git a/src/libcollections/linked_list.rs b/src/libcollections/linked_list.rs
index 7f913d4afe4..d4f77d625b3 100644
--- a/src/libcollections/linked_list.rs
+++ b/src/libcollections/linked_list.rs
@@ -65,6 +65,15 @@ pub struct Iter<'a, T: 'a> {
     marker: PhantomData<&'a Node<T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Iter<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Iter")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 // FIXME #19839: deriving is too aggressive on the bounds (T doesn't need to be Clone).
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> Clone for Iter<'a, T> {
@@ -82,6 +91,15 @@ pub struct IterMut<'a, T: 'a> {
     len: usize,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for IterMut<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("IterMut")
+         .field(self.clone())
+         .finish()
+    }
+}
+
 /// An iterator over the elements of a `LinkedList`.
 #[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -89,6 +107,15 @@ pub struct IntoIter<T> {
     list: LinkedList<T>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("IntoIter")
+         .field(self.clone())
+         .finish()
+    }
+}
+
 impl<T> Node<T> {
     fn new(element: T) -> Self {
         Node {
@@ -1078,6 +1105,17 @@ pub struct FrontPlace<'a, T: 'a> {
 }
 
 #[unstable(feature = "collection_placement",
+           reason = "struct name and placement protocol are subject to change",
+           issue = "30172")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for FrontPlace<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("FrontPlace")
+         .field(self.clone())
+         .finish()
+    }
+}
+
+#[unstable(feature = "collection_placement",
            reason = "placement protocol is subject to change",
            issue = "30172")]
 impl<'a, T> Placer<T> for FrontPlace<'a, T> {
@@ -1122,6 +1160,17 @@ pub struct BackPlace<'a, T: 'a> {
 }
 
 #[unstable(feature = "collection_placement",
+           reason = "struct name and placement protocol are subject to change",
+           issue = "30172")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for BackPlace<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("BackPlace")
+         .field(self.clone())
+         .finish()
+    }
+}
+
+#[unstable(feature = "collection_placement",
            reason = "placement protocol is subject to change",
            issue = "30172")]
 impl<'a, T> Placer<T> for BackPlace<'a, T> {
diff --git a/src/libcollections/str.rs b/src/libcollections/str.rs
index 458d5114829..87315fff0a0 100644
--- a/src/libcollections/str.rs
+++ b/src/libcollections/str.rs
@@ -19,6 +19,7 @@
 // It's cleaner to just turn off the unused_imports warning than to fix them.
 #![allow(unused_imports)]
 
+use core::fmt;
 use core::str as core_str;
 use core::str::pattern::Pattern;
 use core::str::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher};
@@ -122,6 +123,13 @@ pub struct EncodeUtf16<'a> {
     encoder: Utf16Encoder<Chars<'a>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a> fmt::Debug for EncodeUtf16<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.pad("EncodeUtf16 { .. }")
+    }
+}
+
 #[stable(feature = "encode_utf16", since = "1.8.0")]
 impl<'a> Iterator for EncodeUtf16<'a> {
     type Item = u16;
diff --git a/src/libcollections/string.rs b/src/libcollections/string.rs
index 9a985061ebb..4c82e2e2e7e 100644
--- a/src/libcollections/string.rs
+++ b/src/libcollections/string.rs
@@ -1990,6 +1990,13 @@ pub struct Drain<'a> {
     iter: Chars<'a>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a> fmt::Debug for Drain<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.pad("Drain { .. }")
+    }
+}
+
 #[stable(feature = "drain", since = "1.6.0")]
 unsafe impl<'a> Sync for Drain<'a> {}
 #[stable(feature = "drain", since = "1.6.0")]
diff --git a/src/libcollections/vec.rs b/src/libcollections/vec.rs
index c45518438bd..dc0f33d9bc3 100644
--- a/src/libcollections/vec.rs
+++ b/src/libcollections/vec.rs
@@ -2089,6 +2089,15 @@ pub struct Drain<'a, T: 'a> {
     vec: Shared<Vec<T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Drain<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Drain")
+         .field(&self.iter.as_slice())
+         .finish()
+    }
+}
+
 #[stable(feature = "drain", since = "1.6.0")]
 unsafe impl<'a, T: Sync> Sync for Drain<'a, T> {}
 #[stable(feature = "drain", since = "1.6.0")]
@@ -2155,6 +2164,7 @@ impl<'a, T> FusedIterator for Drain<'a, T> {}
 #[unstable(feature = "collection_placement",
            reason = "struct name and placement protocol are subject to change",
            issue = "30172")]
+#[derive(Debug)]
 pub struct PlaceBack<'a, T: 'a> {
     vec: &'a mut Vec<T>,
 }
diff --git a/src/libcollections/vec_deque.rs b/src/libcollections/vec_deque.rs
index 5e1adb3d808..8d42045ff16 100644
--- a/src/libcollections/vec_deque.rs
+++ b/src/libcollections/vec_deque.rs
@@ -1856,6 +1856,15 @@ pub struct Iter<'a, T: 'a> {
     head: usize,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Iter<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Iter")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 // FIXME(#19839) Remove in favor of `#[derive(Clone)]`
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> Clone for Iter<'a, T> {
@@ -1928,6 +1937,15 @@ pub struct IterMut<'a, T: 'a> {
     head: usize,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for IterMut<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("IterMut")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T> Iterator for IterMut<'a, T> {
     type Item = &'a mut T;
@@ -1994,6 +2012,15 @@ pub struct IntoIter<T> {
     inner: VecDeque<T>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("IntoIter")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> Iterator for IntoIter<T> {
     type Item = T;
@@ -2037,6 +2064,15 @@ pub struct Drain<'a, T: 'a> {
     deque: Shared<VecDeque<T>>,
 }
 
+#[stable(feature = "collection_debug", since = "1.17.0")]
+impl<'a, T: 'a + fmt::Debug> fmt::Debug for Drain<'a, T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Drain")
+         .field(&self.clone())
+         .finish()
+    }
+}
+
 #[stable(feature = "drain", since = "1.6.0")]
 unsafe impl<'a, T: Sync> Sync for Drain<'a, T> {}
 #[stable(feature = "drain", since = "1.6.0")]