load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.
Please test any code you have that uses the C standard locale functions!
Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)
convenient when the source string isn't null-terminated.
Implement the other conversion functions (mbstowcs(), mbsrtowcs(), wcstombs(),
wcsrtombs()) in terms of these new functions.