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

[David Spickett via Phabricator via libcxx-commits]

DavidSpickett added a comment.

> Nothing wrong with cppreference, but for the Standard wording we usually use http://eel.is/c++draft/locale.time.get.virtuals#lib:do_get_date,time_get. (Not sure whether you know this resource.)

I didn't, that's much better since cppreference has some of the descriptions merged.

> I think libstdc++'s behaviour is the correct behaviour. But fixing that should be a separate review.

I think I see the logic there now. For MM/DD/YYYY "13/01/2022", the "1" could be part of a valid date ("1/01/2022"), but "13" could not. For the "00/" case, you can have one leading zero so "0" could possibly be part of a valid date ("01/01/2022") but "00" cannot be.



================
Comment at: libcxx/test/std/localization/locale.categories/category.time/locale.time.get.byname/get_date.pass.cpp:114
+        // We consume the first two chars checking the month.
+        assert(base(i) == in+2);
+        // tm is not modified.
----------------
Mordante wrote:
> This should be guarded with
> ```
> #if _LIBCPP_VERSION
>         assert(base(i) == in+2);
> #else
>         assert(base(i) == in+2);
> #endif
> ```
> Our tests should be portable and MSVC STL and GCC use them.
I'll confirm what MSVC does and add these guards.


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  https://reviews.llvm.org/D124175/new/

https://reviews.llvm.org/D124175