On 08/05/17 11:53 +0200, Florian Weimer via libstdc++ wrote:
On 05/05/2017 07:05 PM, Jonathan Wakely wrote:
As discussed at http://stackoverflow.com/q/43769773/981959 (and kinda
hinted at by http://wg21.link/lwg1200) there's a problem with
char_traits<char16_t>::eof() because it returns int_type(-1) which is
the same value as u'\uFFFF', a valid UTF-16 code point.
I think the real bug is that char_traits<char16_t>::int_type is just
plain wrong. It has to be a signed integer,
Why does it have to be signed?
and capable of
representing values in the range 0 .. 65535. char_traits<char32_t>
has a similar problem. char_traits<wchar_t> should be fine on glibc
because WEOF is reserved, something that is probably not the case for
char32_t.
I think there are 32-bit values which are not valid UTF-32 code
points, including char32_t(-1) which we use for EOF.
