Re: [PATCH] Support for C++0x and C1x u8 string literals and raw string literals

[Jakub Jelinek <jakub@redhat.com>]

On Fri, Sep 12, 2008 at 03:56:38PM +0000, Joseph S. Myers wrote:
> > be really pedantic and accept only basic source charset character except
> > the listed 7, rather than say all characters except the listed 7
> > plus maybe disallowing '\0', as this is a new feature I think being
> 
> > pedantic doesn't hurt.  In one of the raw string papers floating
> > around there was an example using R"@[...]@" which is not pedantically
> > valid, as @ is not basic source charset character.  u8 string
> 
> But that example is conditionally valid in C++ only, although not in C, 
> because in phase 1 @ will have been converted to a UCN (part of the 
> existing C++98 semantics we don't implement).  The validity is only 
> conditional because there is no requirement to use the same UCN for each 
> instance of @.

UCNs aren't valid in d-char-sequence though, only in normal strings and within
r-char-sequence.

raw-string:
      " d-char-sequenceopt [ r-char-sequenceopt ] d-char-sequenceopt "
r-char-sequence:
      r-char
      r-char-sequence r-char
r-char:
      any member of the source character set, except
             (1), a backslash \followed by a u or U, or
             (2), a right square bracket ] followed by the initial d-char-sequence
             (which may be empty) followed by a double quote ".
      universal-character-name
d-char-sequence:
      d-char
      d-char-sequence d-char
d-char:
      any member of the basic source character set except:
            space, the left square bracket [, the right square bracket ],
            and the control characters representing horizontal tab,
            vertical tab, form feed, and newline.

	Jakub