[libcxx-commits] [PATCH] D124175: [libcxx] Reject month 0 in get_date/__get_month

[David Spickett via Phabricator via libcxx-commits]

DavidSpickett added a comment.

For https://github.com/llvm/llvm-project/issues/47663.

That's a lot of boilerplate for the tests but I figured I'd stay focused on the problem at hand. (and there are probably reasons for that style)

I did notice that libstdc++ differs in its return value for the failures. It will consume just one character, even if the month is "13" where libcxx consumes both.

  $ /tmp/test_libcxx.o
  Parsing the date out of '13/01/2013' in the locale en_US.utf8
  Parse failed. Unparsed string: /01/2013
  $ g++ /tmp/test.cpp -o /tmp/test.o && /tmp/test.o
  Parsing the date out of '13/01/2013' in the locale en_US.utf8
  Parse failed. Unparsed string: 3/01/2013

>From https://en.cppreference.com/w/cpp/locale/time_get/get_date (not sure if I should be getting the actual standard document for this) this seems like it could be ok.

I read in a draft standard for `do_get_date` specifically "Returns: An iterator pointing immediately beyond the last character recognized as possibly part of a valid date.". So "possibly" seems like it would allow for both behaviours.


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https://reviews.llvm.org/D124175