https://gcc.gnu.org/bugzilla/show_bug.cgi?id=9635
--- Comment #12 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #11)
> We could also have a custom facet derived from time_get that we store in the
> std::locale when it is created by name from a C locale, and store a
> dateorder enum in that derived type on construction. That would allow
> std::time_get facets that are associated with a C locale to return a correct
> dateorder for the locale (but only if the locale's D_FMT happens to map to
> one of the four distinct dateorder formats!)
Like so ...
--- a/libstdc++-v3/src/c++11/localename.cc
+++ b/libstdc++-v3/src/c++11/localename.cc
@@ -36,6 +36,43 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
using namespace __gnu_cxx;
+ template<typename C>
+ struct __time_get : std::time_get<C>
+ {
+ explicit
+ __time_get(time_base::dateorder ord, size_t refs = 0)
+ : time_get<C>(refs), _M_order(ord)
+ { }
+
+ time_base::dateorder do_date_order() const override { return _M_order; }
+
+ time_base::dateorder _M_order;
+ };
+
+ inline template class __time_get<char>;
+#ifdef _GLIBCXX_USE_WCHAR_T
+ inline template class __time_get<wchar_t>;
+#endif
+
+ static inline time_base::dateorder
+ get_date_order(__timepunct<char>* tp)
+ {
+ const char* dates[2];
+ tp->_M_date_formats(dates);
+ if (const char* d = dates[0])
+ {
+ if (!strcmp(d, "%d/%m/%y"))
+ return time_base::dmy;
+ if (!strcmp(d, "%m/%d/%y"))
+ return time_base::mdy;
+ if (!strcmp(d, "%y/%m/%d"))
+ return time_base::ymd;
+ if (!strcmp(d, "%y/%d/%m"))
+ return time_base::ydm;
+ }
+ return time_base::no_order;
+ }
+
static inline bool
is_C_locale(const char* s)
{
@@ -266,8 +303,10 @@ const int num_facets = (
_M_init_facet(new moneypunct<char, true>(__cloc, 0));
_M_init_facet(new money_get<char>);
_M_init_facet(new money_put<char>);
- _M_init_facet(new __timepunct<char>(__cloc, __s));
- _M_init_facet(new time_get<char>);
+ auto tp = new __timepunct<char>(__cloc, __s);
+ _M_init_facet(tp);
+ auto ord = get_date_order(tp);
+ _M_init_facet(new __time_get<char>(ord));
_M_init_facet(new time_put<char>);
_M_init_facet(new std::messages<char>(__cloc, __s));
@@ -283,7 +322,7 @@ const int num_facets = (
_M_init_facet(new money_get<wchar_t>);
_M_init_facet(new money_put<wchar_t>);
_M_init_facet(new __timepunct<wchar_t>(__cloc, __s));
- _M_init_facet(new time_get<wchar_t>);
+ _M_init_facet(new time_get<wchar_t>(ord));
_M_init_facet(new time_put<wchar_t>);
_M_init_facet(new std::messages<wchar_t>(__cloc, __s));
#endif
