Add device_mut method to DeviceWrapper

To prepare the mutability refactoring, we add a device_mut method to
DeviceWrapper that can be used to obtain a mutable reference to the
wrapped device.

2 files changed, 8 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index fcba0f3..718b796 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,7 @@ SPDX-License-Identifier: MIT
 - Add `set_encrypted_volume_mode` to `Storage`.
 - Use mutability to represent changes to the device status:
   - Implement `DerefMut` for `User<T>` and `Admin<T>`.
+  - Add `device_mut` method to `DeviceWrapper`.
 
 # v0.3.4 (2019-01-20)
 - Fix authentication methods that assumed that `char` is signed.
diff --git a/src/device.rs b/src/device.rs
index c985802..462e9dc 100644
--- a/src/device.rs
+++ b/src/device.rs
@@ -728,6 +728,13 @@ impl DeviceWrapper {
             DeviceWrapper::Pro(ref pro) => pro,
         }
     }
+
+    fn device_mut(&mut self) -> &mut dyn Device {
+        match *self {
+            DeviceWrapper::Storage(ref mut storage) => storage,
+            DeviceWrapper::Pro(ref mut pro) => pro,
+        }
+    }
 }
 
 impl From<Pro> for DeviceWrapper {