Register<T> extension for IDependencyCollection.

RELEASE-NOTES.md

@@ -47,6 +47,7 @@ Template for new versions:
     * `IClyde.TextInputStart()`, `IClyde.TextInputStop()`, `IClyde.TextInputSetRect()` APIs to control text input behavior.
     * `TextEditing` events for reporting in-progress IME compositions.
     * `LineEdit` and `TextEdit` have functional IME support when the game is running on SDL2. If you provide a font file with the relevant glyphs, CJK text input should now be usable.
+* `Register<T>` (single type parameter) extension method for `IDependencyCollection`.
 
 ### Bugfixes
 

Robust.Shared/IoC/DependencyCollectionExt.cs

@@ -0,0 +1,20 @@
+using JetBrains.Annotations;
+
+namespace Robust.Shared.IoC;
+
+/// <summary>
+/// Extension methods for <see cref="IDependencyCollection"/>.
+/// </summary>
+public static class DependencyCollectionExt
+{
+    /// <summary>
+    /// Register a type as both implementation and interface.
+    /// This is equivalent to calling <see cref="IDependencyCollection.Register{TInterface, TImplementation}(bool)"/> with both type args set to <typeparamref name="T"/>.
+    /// </summary>
+    /// <param name="deps">The dependency collection to register into.</param>
+    public static void Register<[MeansImplicitUse] T>(this IDependencyCollection deps)
+        where T : class
+    {
+        deps.Register<T, T>();
+    }
+}