DefaultValuesHandling is not a valid named attribute argument because it is not a valid attribute parameter type

[Phyksar]

DefaultValuesHandling attribute is not usable in Visual Studio 2019, I assume this is because it is declared as nullable enum.

YamlDotNet/YamlDotNet/Serialization/YamlMember.cs

Line 61 in bb70515

public DefaultValuesHandling? DefaultValuesHandling { get; set; }

When using it on a class field compiler outputs following message:

Severity  Code    Description
Error	  CS0655  'DefaultValuesHandling' is not a valid named attribute argument because it is not a valid attribute parameter type

[aaubry]

Thanks for reporting this problem. I'll look into this and get back to you, hopefully tomorrow.

[aaubry]

Of course you're right. We can't use nullables in custom attributes. I'll fix that.