Fix nullable annotations for ImmutableArray cast methods (dotnet#40084)

* Fix nullable annotations for ImmutableArray cast methods, Fixes dotnet#39799 * address feedback
elinor-fung · Aug 3, 2020 · f1911f3 · f1911f3
1 parent f3b8255
commit f1911f3
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Showing 2 changed files with 7 additions and 7 deletions.
diff --git a/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs b/src/libraries/System.Collections.Immutable/ref/System.Collections.Immutable.cs
@@ -122,9 +122,9 @@ public partial struct ImmutableArray<T> : System.Collections.Generic.ICollection
         public System.ReadOnlyMemory<T> AsMemory() { throw null; }
         public System.ReadOnlySpan<T> AsSpan() { throw null; }
 #endif
-        public System.Collections.Immutable.ImmutableArray<TOther> As<TOther>() where TOther : class { throw null; }
-        public System.Collections.Immutable.ImmutableArray<TOther> CastArray<TOther>() where TOther : class { throw null; }
-        public static System.Collections.Immutable.ImmutableArray<T> CastUp<TDerived>(System.Collections.Immutable.ImmutableArray<TDerived> items) where TDerived : class, T { throw null; }
+        public System.Collections.Immutable.ImmutableArray<TOther> As<TOther>() where TOther : class? { throw null; }
+        public System.Collections.Immutable.ImmutableArray<TOther> CastArray<TOther>() where TOther : class? { throw null; }
+        public static System.Collections.Immutable.ImmutableArray<T> CastUp<TDerived>(System.Collections.Immutable.ImmutableArray<TDerived> items) where TDerived : class?, T { throw null; }
         public System.Collections.Immutable.ImmutableArray<T> Clear() { throw null; }
         public bool Contains(T item) { throw null; }
         public void CopyTo(int sourceIndex, T[] destination, int destinationIndex, int length) { }

diff --git a/...System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Minimal.cs b/...System.Collections.Immutable/src/System/Collections/Immutable/ImmutableArray_1.Minimal.cs
@@ -334,7 +334,7 @@ public bool Equals(ImmutableArray<T> other)
         /// <see cref="ImmutableArray{T}.As{TOther}"/>  or <see cref="ImmutableArray{T}.CastArray{TOther}"/>method.
         /// </remarks>
         public static ImmutableArray<T> CastUp<TDerived>(ImmutableArray<TDerived> items)
-            where TDerived : class, T
+            where TDerived : class?, T
         {
             return new ImmutableArray<T>(items.array);
         }
@@ -344,7 +344,7 @@ public static ImmutableArray<T> CastUp<TDerived>(ImmutableArray<TDerived> items)
         /// array to an array of type <typeparam name="TOther"/>.
         /// </summary>
         /// <exception cref="InvalidCastException">Thrown if the cast is illegal.</exception>
-        public ImmutableArray<TOther> CastArray<TOther>() where TOther : class
+        public ImmutableArray<TOther> CastArray<TOther>() where TOther : class?
         {
             return new ImmutableArray<TOther>((TOther[])(object)array!);
         }
@@ -364,9 +364,9 @@ public ImmutableArray<TOther> CastArray<TOther>() where TOther : class
         /// element types to their derived types. However, downcasting is only successful
         /// when it reverses a prior upcasting operation.
         /// </remarks>
-        public ImmutableArray<TOther> As<TOther>() where TOther : class
+        public ImmutableArray<TOther> As<TOther>() where TOther : class?
         {
-            return new ImmutableArray<TOther>((this.array as TOther[])!);
+            return new ImmutableArray<TOther>((this.array as TOther[]));
         }
 
         /// <summary>