Code deduplication

src/Avalonia.Base/Data/Converters/FuncValueConverter.cs

@@ -26,7 +26,7 @@ namespace Avalonia.Data.Converters
         /// <inheritdoc/>
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is TIn || (value == null && TypeUtilities.AcceptsNull<TIn>()))
+            if (TypeUtilities.CanCast<TIn>(value))
             {
                 return _convert((TIn)value);
             }