static locale global(const locale& loc);
Effects: Causes future calls to the constructor locale() to return a copy of the argument. If the argument has a name, does
setlocale(LC_ALL, loc.name().c_str());
otherwise, the effect on the C locale, if any, is implementation-defined. No library function other than locale::global() shall affect the value returned by locale(). [ Note: See [c.locales] for data race considerations when setlocale is invoked. — end note ]
static const locale& classic();
Returns: A locale that implements the classic "C" locale semantics, equivalent to the value locale("C").