What does [CallerArgumentExpression] capture, and how do I use it in my own guard methods?
[CallerArgumentExpression] makes the C# compiler pass the source text of an argument as a string. Verified on .NET 10 and C# 14: what exactly gets captured (whitespace, comments, parentheses, line breaks), when you get null instead, how to write NotNull, Positive and That guards, and the overload trap that silently disables it.