This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 110b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Voted into WP at October, 2009 meeting.]
The description of concatenation of string literals in 5.13.5 [lex.string] paragraph 11 does not mention raw strings explicitly, so it is not clear whether, and if so, how, they combine with non-raw strings.
Notes from the March, 2009 meeting:
A raw string should be considered equivalent to the corresponding non-raw string in string literal concatenation.
Proposed resolution (September, 2009):
In 5.13.5 [lex.string], replace the definition of string-literal with:
Change 5.13.5 [lex.string] paragraph 5 as follows:
Astring literal that does not begin with u8, u, U, or Lis an ordinary string literal, and is initialized with the given characters.
Change 5.13.5 [lex.string] paragraph 12 as follows:
In translation phase 6 (5.2 [lex.phases]), adjacent string literals are concatenated. If both string literals have the same
prefix, the resulting concatenated string literal has that prefix. If one string literal has no prefix, it is treated as a string literal of the same prefixas the other operand. If a UTF-8 string literal token is adjacent to a wide string literal token, the program is ill-formed. Any other concatenations are conditionally supported with implementation-defined behavior. [Note: This concatenation is an interpretation, not a conversion. —end note] [Example:...
(Note: this resolution also resolves issue 834.)