anchor.diff:  
   | Module initializers  | *[ModuleInitializer]* _Method_() { … }  | 9.0  | 2020-11-10
   
  -| Named arguments  | _Method_( *paramName:* value)  | 4.0  | 2010-04-12
  -
   | Nameof operator  | ⌨️ *nameof()*  | 6.0  | 2014-11-12
   
   | Native sized integers  | ⌨️ *nint* _// System.IntPtr_ ⌨️ *nuint* _// System.UIntPtr_  | 9.0  | 2020-11-10
   
  -| Non-trailing named arguments
  +| Nesting: File scoped namespaces  | namespace _Name_ *;*  | 10.0  | 2021-11-08
  +
  +| Nesting: Top level statements
  +| _// statements in one source file outside any containing method imply program entry point_
  +| 9.0
  +| 2020-11-20
  +
  +| Nesting: Using declarations  | *using var* _x_ = _disposble_; _// applies to end of scope_  | 8.0  | 2019-09-23
  +
  +| Nulls: Null forgiving operator  | ❇️ *!*  | 8.0  | 2019-09-23
  +
  +| Nulls: Null propagator  | ❇️ x**?.**_member_ ❇️ x**?[**_expression_**]**  | 6.0  | 2014-11-12
  +
  +| Nulls: Null-coalescing assignment  | ❇️ *??=*  | 8.0  | 2019-09-23
  +
  +| Nulls: Nullable types  | 🧩 *Nullable<T>* ❇️ _Type_**?**  | 2.0  | 2006-01-22
  +
  +| Nulls: Nullable types: Reference types
  +| _// reference types may not be null without *?*, and require null-checking with it_
  +| 8.0
  +| 2019-09-23
  +
  +| Parameters: Caller info attributes
  +| 🧩 *CallerFilePathAttribute* 🧩 *CallerLineNumberAttribute* 🧩 *CallerMemberNameAttribute*
  +| 5.0
  +| 2012-08-15
  +
  +| Parameters: Caller info attributes: Expression  | 🧩 *CallerArgumentExpressionAttribute*  | 10.0  | 2021-11-08
  +
  +| Parameters: In parameters  | ⌨️ *in*  | 7.2  | 2017-12-04
  +
  +| Parameters: Named arguments  | _Method_( *paramName:* value)  | 4.0  | 2010-04-12
  +
  +| Parameters: Non-trailing named arguments
   | _// named params can precede unnamed ones that are in the right position_
   | 7.2
   | 2017-12-04
   
  -| Null forgiving operator  | ❇️ *!*  | 8.0  | 2019-09-23
  -
  -| Null propagator  | ❇️ x**?.**_member_ ❇️ x**?[**_expression_**]**  | 6.0  | 2014-11-12
  -
  -| Null-coalescing assignment  | ❇️ *??=*  | 8.0  | 2019-09-23
  -
  -| Nullable types  | 🧩 *Nullable<T>* ❇️ _Type_**?**  | 2.0  | 2006-01-22
  -
  -| Nullable types: Reference types
  -| _// reference types may not be null without *?*, and require null-checking with it_
  -| 8.0
  -| 2019-09-23
  -
  -| Out variables  | _Method_(*out var* _param_)  | 7.0  | 2017-04-05
  +| Parameters: Out variables  | _Method_(*out var* _param_)  | 7.0  | 2017-04-05
   
   | Partial classes  | ⌨️ *partial class* ⌨️ *partial interface* ⌨️ *partial struct*  | 2.0  | 2006-01-22
   
  
positive.code: 
  | Pattern matching: Type variables  | _x_ is _type_  | 9.0  | 2020-11-10
  
  | Query expressions
  | ⌨️ *from* _item_ in _Items_ *where* _item != null_ *orderby* _item_ select _item_
  | 3.0
  
negative.code: 
  | Anonymous methods  | ⌨️ *delegate*  | 2.0  | 2006-01-22
  
  | Asynchronous members  | ⌨️ *async* ⌨️ *await*  | 5.0  | 2012-08-15
  
  | Asynchronous streams  | async *IAsyncEnumerable<T>* _Method_( … )  | 8.0  | 2019-09-23
  
  | Default interface methods  | _// provide interface method implementations to inherit_  | 8.0  | 2019-09-23
  
  | Discards  | *_*  | 7.0  | 2017-04-05
  
  | Dynamic binding  | ⌨️ *dynamic*  | 4.0  | 2010-04-12
  
  | Exceptions: Exception filters  | catch (_ExceptionType e_) *when _expression_*  | 6.0  | 2014-11-12
  
  | Exceptions: Throw expressions
  | _expr_ ? _expr_ : throw _exception_ 〰️ _x_ ?? throw _exception_ 〰️ _Member_ => throw _exception_
  | 7.0
  | 2017-04-05
  
  | Expression bodied members
  | _Member_ *=>* _expression_; _// method, operator, or read-only property_
  