Fixed array covariance

src/DotNext.Tests/Runtime/ValueReferenceTests.cs

@@ -157,6 +157,16 @@ public static void BoxedValueInterop()
         Equal(boxedInt.Value, reference.Value);
     }
 
+    [Fact]
+    public static void ArrayCovariance()
+    {
+        string[] array = ["a", "b"];
+        Throws<ArrayTypeMismatchException>(() => new ValueReference<object>(array, 0));
+
+        var roRef = new ReadOnlyValueReference<object>(array, 1);
+        Equal("b", roRef.Value);
+    }
+
     private record class MyClass : IResettable
     {
         internal static string StaticObject;

src/DotNext/Runtime/ValueReference.cs

@@ -26,6 +26,9 @@ public readonly struct ValueReference<T>(object owner, ref T fieldRef) :
     /// </summary>
     /// <param name="array">The array.</param>
     /// <param name="index">The index of the array element.</param>
+    /// <exception cref="ArrayTypeMismatchException">
+    /// <typeparamref name="T"/> is a reference type, and <paramref name="array" /> is not an array of type <typeparamref name="T"/>.
+    /// </exception>
     public ValueReference(T[] array, int index)
         : this(array, ref array[index])
     {
@@ -131,6 +134,16 @@ public readonly struct ReadOnlyValueReference<T>(object owner, ref readonly T fi
 {
     private readonly nint offset = RawData.GetOffset(owner, in fieldRef);
 
+    /// <summary>
+    /// Creates a reference to an array element.
+    /// </summary>
+    /// <param name="array">The array.</param>
+    /// <param name="index">The index of the array element.</param>
+    public ReadOnlyValueReference(T[] array, int index)
+        : this(array, in array[index])
+    {
+    }
+
     /// <summary>
     /// Creates a reference to a static field.
     /// </summary>