Expression Variables

The expression variables feature extends the features introduced in C# 7 to permit expressions containing expression variables (out variable declarations and declaration patterns) in field initializers, property initializers, ctor-initializers, and query clauses.

See https://github.com/dotnet/csharplang/issues/32 and https://github.com/dotnet/csharplang/blob/main/proposals/csharp-7.3/expression-variables-in-initializers.md for more information.

Current state of the feature:

[X] Permit in field initializers [X] Permit in property initializers [ ] Permit in ctor-initializers [X] Permit in query clauses