I was reading through the Working Draft of C++ and was surprised when I came across the seemingly simplest feature of programming: Comments! (and even more surprised that I didn't find anything about the behavior of escape sequences in comments!)
Quote from the C++ draft:
If there is a form-feed or a vertical-tab character in such a comment, only whitespace characters shall appear between it and the new-line that terminates the comment; no diagnostic is required.
I struggle in what exactly is meant by this quote.
I came up with this:
// This is a comment\f \tThis is still part of the comment\nThis is not part of the comment
As it seems, escape sequences have influences on comments, so I played around with it for a while but didn't come to a major conclusion.
// This is a comment\nThis is not part of the comment
As they say in the draft:
which terminates immediately before the next new-line character
So I figured, if I just put a newline character in the comment myself, the rest of the comment doesn't get treated as a 'comment'? But it kind of does..? What is the deal with that?
"If there is a form-feed or a vertical-tab character in such a comment, only whitespace characters shall appear between it and the new-line that terminates the comment; no diagnostic is required."
This talks about literal form-feed and vertical-tab characters, not escape sequences (which are not interpreted in comments).
A valid comment:
// comment<a literal vertical-tab><whitespaces...><newline>
Also valid:
// hello\f\f\f\fworld<newline>
Here's an invalid comment, because the vertical-tab is followed by something else than only whitespace characters before the newline:
// comment<a literal vertical-tab><whitespaces...>FOO<newline>
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