Added support for pointer and by-ref types

Author: Sergio0694

Microsoft.Toolkit/Extensions/TypeExtensions.cs

@@ -154,10 +154,34 @@ static string FormatDisplayString(Type type, int genericTypeOffset, ReadOnlySpan
             }
 
             // Atomically get or build the display string for the current type.
-            // Manually create a static lambda here to enable caching of the generated closure.
-            // This is a workaround for the missing caching for method group conversions, and should
-            // be removed once this issue is resolved: https://github.com/dotnet/roslyn/issues/5835.
-            return DisplayNames.GetValue(type, t => FormatDisplayString(t, 0, type.GetGenericArguments()));
+            return DisplayNames.GetValue(type, t =>
+            {
+                // By-ref types are displayed as T&
+                if (t.IsByRef)
+                {
+                    t = t.GetElementType();
+
+                    return $"{FormatDisplayString(t, 0, type.GetGenericArguments())}&";
+                }
+
+                // Pointer types are displayed as T*
+                if (t.IsPointer)
+                {
+                    int depth = 0;
+
+                    // Calculate the pointer indirection level
+                    while (t.IsPointer)
+                    {
+                        depth++;
+                        t = t.GetElementType();
+                    }
+
+                    return $"{FormatDisplayString(t, 0, type.GetGenericArguments())}{new string('*', depth)}";
+                }
+
+                // Standard path for concrete types
+                return FormatDisplayString(t, 0, type.GetGenericArguments());
+            });
         }
 
         /// <summary>

UnitTests/UnitTests.Shared/Extensions/Test_TypeExtensions.cs

@@ -73,6 +73,39 @@ public void Test_TypeExtensions_NestedTypes(string name, Type type)
             Assert.AreEqual(name, type.ToTypeString());
         }
 
+#pragma warning disable SA1015 // Closing generic brackets should be spaced correctly
+        [TestCategory("TypeExtensions")]
+        [TestMethod]
+        [DataRow("void*", typeof(void*))]
+        [DataRow("int**", typeof(int**))]
+        [DataRow("byte***", typeof(byte***))]
+        [DataRow("System.Guid*", typeof(Guid*))]
+        [DataRow("UnitTests.Extensions.Foo<int>*", typeof(Foo<int>*))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat**", typeof(Animal.Cat**))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<int>*", typeof(Animal.Cat<int>*))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<float>.Bar**", typeof(Animal.Cat<float>.Bar**))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<double>.Bar<int>***", typeof(Animal.Cat<double>.Bar<int>***))]
+        public void Test_TypeExtensions_PointerTypes(string name, Type type)
+        {
+            Assert.AreEqual(name, type.ToTypeString());
+        }
+#pragma warning restore SA1015
+
+        [TestCategory("TypeExtensions")]
+        [TestMethod]
+        [DataRow("int&", typeof(int))]
+        [DataRow("byte&", typeof(byte))]
+        [DataRow("System.Guid&", typeof(Guid))]
+        [DataRow("UnitTests.Extensions.Foo<int>&", typeof(Foo<int>))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat&", typeof(Animal.Cat))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<int>&", typeof(Animal.Cat<int>))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<float>.Bar&", typeof(Animal.Cat<float>.Bar))]
+        [DataRow("UnitTests.Extensions.Test_TypeExtensions.Animal.Cat<double>.Bar<int>&", typeof(Animal.Cat<double>.Bar<int>))]
+        public void Test_TypeExtensions_RefTypes(string name, Type type)
+        {
+            Assert.AreEqual(name, type.MakeByRefType().ToTypeString());
+        }
+
         private class Animal
         {
             public struct Cat