Undocumented C# Keyword

[Youssef1313]

Reading through CA2230, it mentions __arglist as a C# Keyword. I never knew the existence of such keyword in C#.
Searching through the documentation doesn't give any results (To be accurate, only results in error messages, not actual documentation for the keyword).

So, I suspect the documentation is missing this keyword.

The documentation for that keyword should also include a note that it's preferred to use params.

[svick]

I believe __arglist (and keywords related to it) is intentionally undocumented, because it shouldn't be used. That's also why it starts with double underscore. I don't think there's any reason to start documenting it now.

[Youssef1313]

@svick, Thanks for answering. But are there any rare scenarios where one would use __arglist? for interop with C/C++ for example? or it's always bad to use it?

[BillWagner]

The last section of identifies in the C# spec has the following text:

Identifiers containing two consecutive underscore characters (U+005F) are reserved for use by the implementation. For example, an implementation might provide extended keywords that begin with two underscores.

I think that is sufficient. I recommend closing this.