RUST-1534: implement iter_mut on Document (#382)

Author: abr-egn

src/document.rs

@@ -117,6 +117,11 @@ pub struct Values<'a> {
     inner: indexmap::map::Values<'a, String, Bson>,
 }
 
+/// An iterator over a `Document`'s keys and mutable values.
+pub struct IterMut<'a> {
+    inner: indexmap::map::IterMut<'a, String, Bson>,
+}
+
 impl<'a> Iterator for Keys<'a> {
     type Item = &'a String;
 
@@ -181,6 +186,14 @@ impl<'a> Iterator for Iter<'a> {
     }
 }
 
+impl<'a> Iterator for IterMut<'a> {
+    type Item = (&'a String, &'a mut Bson);
+
+    fn next(&mut self) -> Option<(&'a String, &'a mut Bson)> {
+        self.inner.next()
+    }
+}
+
 impl Document {
     /// Creates a new empty Document.
     pub fn new() -> Document {
@@ -194,6 +207,13 @@ impl Document {
         self.into_iter()
     }
 
+    /// Gets an iterator over pairs of keys and mutable values.
+    pub fn iter_mut(&mut self) -> IterMut {
+        IterMut {
+            inner: self.inner.iter_mut(),
+        }
+    }
+
     /// Clears the document, removing all values.
     pub fn clear(&mut self) {
         self.inner.clear();

src/raw/document.rs

@@ -28,7 +28,7 @@ use crate::{oid::ObjectId, spec::ElementType, Document};
 
 /// A slice of a BSON document (akin to [`std::str`]). This can be created from a
 /// [`RawDocumentBuf`] or any type that contains valid BSON data, including static binary literals,
-/// [Vec<u8>](std::vec::Vec), or arrays.
+/// [`Vec<u8>`](std::vec::Vec), or arrays.
 ///
 /// This is an _unsized_ type, meaning that it must always be used behind a pointer like `&`. For an
 /// owned version of this type, see [`RawDocumentBuf`].