Paul Mensonides wrote:
-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Edward Diener
I have never understood the definition of a pp-number in the C++ standard. I am using the 1998 version and I read:
ppnumber: digit . digit ppnumber digit ppnumber nondigit ppnumber e sign ppnumber E sign ppnumber .
Since "ppnumber digit" and "ppnumber nondigit" covers all sequences beginning either with a "digit" or a ".digit" followed by anything else which is not a whitespace character or a comment, why specify the last three items ?
Despite the name, 'nondigit' is not any non-digit character. It is just the alphabetic characters, the underscore, and universal character names (subject to annex E).
Thanks, I see it now. The definition of non-digit ( and digit ) unfortunately was made not in Preprocessing Numbers section, where it was first mentioned, but in the Identifiers section. Thanks for pointing this out to me.