aqua.tool.polyfill.IsExternalInit (nuget): C# source code only package which allows you to use C# 9.0's 'init only setters' feature targeting frameworks older than net5.0.  This package generats a polyfill type to resolve "Error CS0518 - Predefined type 'System.Runtime.CompilerServices.IsExternalInit' is not defined or imported".
Keywords: c#|csharp|init|initonly|init-only-setters