Keith Pinson

The way I understand the [license](https://visualstudiogallery.msdn.microsoft.com/site/1f2ee1da-e87f-4863-b98e-d8b7b63d2253/eula?licenseType=None) for that project, I don't think it will be a hindrance. However, it is for VS 2010 and does not seem to have been...

**EDIT**: the below is the original post, but a warning to those who find it hereafter that this did *not* work. --- A coworker discovered a workaround which looks like...

> which looks like it will suffice for our case Well, I hope. I have not fully validated this hope yet.

@soujiro32167 unless you have the null second, which is the way that Avro4s has it IIRC.

Oh, Avro4s seems to change the way its option codecs work based on the default, sometimes putting `null` first, sometimes not.

[This](https://github.com/fd4s/vulcan/issues/518#issuecomment-1505761275) did **not** work. Looks like this will, however: ```scala private implicit lazy val optionAllowingDefaultSome : Codec[Option[Int]] = Codec.union(builder => builder[Some[Int]] builder[None.type] ) ``` A locally-scoped monomorphic implicit that puts...

This fixed it for me, thanks. :tada:

If it is useful, I now have a [branch](https://github.com/Kazark/fsharp-srtp-broken/tree/feature-fixed) where I got the compile to fail by using more member constraints to fake out type-level guarantees on the conceptual higher-kinded...

@abelbraaksma Thanks for your intriguing comments. I will certainly own up to the fact that this is insanely complex SRTP code. Polite of you to say you are impressed; you...

@drvink Wow, thanks for the detailed response. I may respond more after digesting it.