Making the latest C# language features available in older .NET versions

In a C# library I’ve been working on, I wanted to use C# 9.0’s init keyword. Quoting the documentation: The init keyword defines an accessor method in a property or indexer. An init-only setter assigns a value to the property or the indexer element only during object construction. This enforces immutability so that once the object is initialized, it can’t be changed again. Consider the following class: public class Person { public string FirstName { get; init; } } You can initialize it like this: »