Compiler Errors under VS2019 in Appveyor CI

[dota17]

Recently, Appveyor CI had a lot of compiler errors under VS2019.
Since 3/20, all pr have the same compiler errors:

C:\projects\json\test\src\unit-conversions.cpp(1387): message : see reference to function template instantiation 'ValueType nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer>::get<std::valarray<std::string>,std::valarray<std::string>,0>(void) noexcept(false) const' being compiled [C:\projects\json\test\test-conversions.vcxproj]
          with
          [
              ValueType=std::valarray<std::string>
          ]
...

#2004 just added wsjcpp.yml, and it got the same errors.

• What is the expected behavior?
  Appveyor CI should pass.

[garethsb]

Resolved by #2008, I think?

[dota17]

Resolved by #2008, I think?

Yes, I had checked and tested in my fork repo.
After merging the PR, the Appveyor CI will pass.

Thanks for your help : ) .
This issue can be closed when the PR #2008 is merged.

[nlohmann]

#2008 was merged. Any ideas on this?

[dota17]

No. This issue can be closed.