PolyType 1.3.1 Eirik Tsarpalis MIT https://licenses.nuget.org/MIT pkgicon.png README.md https://eiriktsarpalis.github.io/PolyType/ Practical generic programming for C# https://github.com/eiriktsarpalis/PolyType/releases/tag/v1.3.1 2024 generic programming, source generator, polytypic