add missing docs

Author: zonyitoo

src/decoder/serde.rs

@@ -143,6 +143,7 @@ impl Visitor for BsonVisitor {
     }
 }
 
+/// Serde Decoder
 pub struct Decoder {
     value: Option<Bson>,
 }

src/encoder/serde.rs

@@ -54,6 +54,7 @@ impl Serialize for Bson {
     }
 }
 
+/// Serde Encoder
 pub struct Encoder;
 
 impl Encoder {

src/macros.rs

@@ -1,3 +1,4 @@
+/// Construct a BSON value
 #[macro_export]
 macro_rules! bson {
     ([]) => {{ $crate::Bson::Array(Vec::new()) }};
@@ -29,6 +30,7 @@ macro_rules! bson {
     }};
 }
 
+/// Construct a BSON Document
 #[macro_export]
 macro_rules! doc {
     () => {{ $crate::Document::new() }};

src/oid.rs

@@ -1,3 +1,5 @@
+//! ObjectId
+
 use libc;
 
 use std::{fmt, io, error, result};

src/ordered.rs

@@ -1,3 +1,5 @@
+//! A BSON document represented as an associative HashMap with insertion ordering.
+
 use std::error;
 use std::fmt::{self, Debug, Display, Formatter};
 use std::iter::{FromIterator, Map};
@@ -17,10 +19,13 @@ use spec::BinarySubtype;
 /// type, for use with the direct getters.
 #[derive(PartialEq)]
 pub enum ValueAccessError {
+    /// Cannot find the expected field with the specified key
     NotPresent,
+    /// Found a Bson value with the specified key, but not with the expected type
     UnexpectedType,
 }
 
+/// Result of accessing Bson value
 pub type ValueAccessResult<T> = Result<T, ValueAccessError>;
 
 impl Debug for ValueAccessError {