DeviceDependentGenerator added.

PerfectNumbers.Core/DeviceDependentTemplateAttribute.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace PerfectNumbers.Core;
+
+[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, Inherited = false, AllowMultiple = false)]
+public sealed class DeviceDependentTemplateAttribute : Attribute
+{
+    public DeviceDependentTemplateAttribute(Type enumType)
+    {
+        EnumType = enumType ?? throw new ArgumentNullException(nameof(enumType));
+    }
+
+    public Type EnumType { get; }
+}
+