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Re: C++ alternative tokens in the preprocessor
"Martin v. Loewis" <martin@loewis.home.cs.tu-berlin.de> writes:
| > [lex.key]/2 says these alternative representations of operators are
| > reserved and shall not be used otherwise. But then, keywords are
| > only meaningful after preprocessing (i.e., you can #define new and
| > delete), so this is a bit fuzzy.
|
| It doesn't say they are keywords, as keywords are listed in Table 3.
| Given that they are explained in 2.5, I'd expect they behave like
| digraphs in all respects.
|
| Another questions is which of
|
| #define P(a,b) a##b
| P(method_,and)
Well-formed.
| P(and,=)
|
| is well-formed; the footnote explicitly mentions that it is spelled
| "and" in stringification, and [cpp.stringize] mentions explicitly that
| the spelling is taken. [cpp.concat] says that the tokens are
| "concatenated", so I'm not sure whether this means that the original
| or the alternative token is concatenated - they are supposed to
| "behave the same" (quote from normative text).
Normative text says:
2.12/1:
Each preprocessing-op-or-punc is converted to a single token in
translation phase 7 (2.1).
Phase 7 happens only after phase 4 where preprocessing diretives are
executed.
-- Gaby
CodeSourcery, LLC http://www.codesourcery.com