DOCSP-39859: What's New 3.0 (#122)

Author: norareidy

source/fundamentals/runtimes.txt

@@ -20,18 +20,6 @@ and structure your code to use each.
 The {+driver-short+} supports the ``tokio`` asynchronous runtime crate, which is the default
 runtime.
 
-.. important::
-
-   Beginning in {+driver-short+} v3.0, the ``tokio`` runtime is the only asynchronous runtime crate that
-   the driver supports. Previous versions of the driver also support the ``async-std`` runtime crate.
-   If your application uses the ``async-std`` runtime, you can start a ``tokio`` runtime in the same
-   application by creating a ``Runtime`` struct instance and wrapping driver operations with the ``Runtime::spawn()``
-   method. Ensure that you use the same ``Runtime`` instance for instantiating a ``Client`` and calling
-   driver methods on that ``Client`` instance.
-   
-   For an example that instantiates a ``Runtime`` and calls the ``spawn()`` method, see the `tokio documentation
-   <https://docs.rs/tokio/latest/tokio/runtime/struct.Runtime.html#examples-2>`__.
-
 The driver also includes a synchronous API for use cases that require blocking, or when parallelism
 is not necessary. You can select the synchronous API by adding feature flags to the ``mongodb`` dependency
 in your ``Cargo.toml`` file.
@@ -63,6 +51,19 @@ the ``mongodb`` dependency. For more information on installing the driver and ad
 including an example that specifies the ``"tokio-runtime"`` feature flag, see the
 :ref:`rust-quick-start-download-and-install` step of the Quick Start.
 
+.. important::
+
+   Beginning in {+driver-short+} v3.0, the ``tokio`` runtime is the only asynchronous runtime crate that
+   the driver supports. Previous versions of the driver also support the ``async-std`` runtime crate.
+   
+   If your application uses the ``async-std`` runtime, you can start a ``tokio`` runtime in the same
+   application by creating a ``Runtime`` struct instance and wrapping driver operations with the ``Runtime::spawn()``
+   method. Ensure that you use the same ``Runtime`` instance for instantiating a ``Client`` and calling
+   driver methods on that ``Client`` instance.
+   
+   For an example that instantiates a ``Runtime`` and calls the ``spawn()`` method, see the `tokio documentation
+   <https://docs.rs/tokio/latest/tokio/runtime/struct.Runtime.html#examples-2>`__.
+
 Tokio Runtime Example
 ~~~~~~~~~~~~~~~~~~~~~
 

source/whats-new.txt

@@ -20,10 +20,70 @@ What's New
 Learn about new features, improvements, and fixes introduced in the
 following versions of the {+driver-long+}:
 
+* :ref:`Version 3.0 <rust-version-3.0>`
 * :ref:`Version 2.8 <rust-version-2.8>`
 * :ref:`Version 2.7 <rust-version-2.7>`
 * :ref:`Version 2.6 <rust-version-2.6>`
 
+.. _rust-version-3.0:
+
+What's New in 3.0
+-----------------
+
+The {+driver-short+} v3.0 release includes the following features, improvements, and fixes:
+
+- Implements a fluent API, which introduces the following syntax changes for passing options and
+  starting sessions:
+
+  - To set asynchronous method options, chain option builder methods directly to the method call
+    instead of passing an options struct parameter.
+  
+  - To set synchronous method options, chain option builder methods to the method call, then
+    call the ``run()`` method.
+  
+  - If you must construct a separate options struct, chain the ``with_options()``
+    method to the method call and pass your options struct as a parameter.
+
+  - To start a session, chain the ``session()`` method to the method call instead of using a separate
+    method that has a ``_with_session`` suffix.
+
+- Adds support for bulk write operations. To learn more about these operations, see the 
+  :ref:`rust-bulk-guide` guide.
+
+- Introduces the ``EventHandler`` type to reduce the amount of boilerplate code required for event monitoring. 
+  For examples that use the ``EventHandler`` type, see the :ref:`rust-monitoring` guides.
+
+- Removes support for the ``async-std`` asynchronous runtime. To learn more about this change, see
+  the :ref:`rust-runtimes-configure-async` section of the Asynchronous and Synchronous APIs guide.
+
+- Requires the use of a ``compat`` feature if a {+driver-short+} application is compiled with
+  the ``no-default-features`` command line flag. The ``rustls`` and ``dns-resolution`` features
+  are now optional.
+
+- Removes support for the ``bson-*`` driver features. You can select these features by including
+  ``bson`` as a direct dependency in your application.
+
+- Removes support for read and write concern constants. Instead, use helper methods to set ``ReadConcern`` and
+  ``WriteConcern`` values.
+
+- Adds ``Send + Sync`` constraints to the ``Collection<T>`` type.
+
+- Removes the ``ClientOptions::compressor`` field if no compressor features are enabled.
+
+- Changes the type of ``ReadPreferenceOptions`` fields. These fields now have a ``Option<ReadPreferenceOptions>`` type.
+
+- Removes the ``CollectionOptions::human_readable_serialization`` option. Instead, use the ``bson::HumanReadable``
+  wrapper type to serialize user data into human-readable form.
+
+- Adds support for value conversion through the ``Into`` trait for all option struct builders.
+
+- Renames the ``comment_bson`` field to ``comment`` for ``AggregateOptions``, ``FindOptions``, and ``FindOneOptions``
+  structs. 
+
+To learn more about this release, see the `v3.0 Migration Guide
+<https://github.com/mongodb/mongo-rust-driver/blob/main/migration-3.0.md>`__
+on GitHub.
+
 .. _rust-version-2.8:
 
 What's New in 2.8