inline SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>&
operator>>(std::basic_istream<Elem, Traits>& lhs, sprout::rational<IntType>& rhs) {
IntType n = IntType(0);
IntType d = IntType(1);
Elem c = 0;
sprout::detail::io::ios_flags_saver saver(lhs);
lhs >> n;
c = lhs.get();
if (c != Elem('/')) {
lhs.clear(std::istream::badbit);
}
lhs >> std::noskipws;
lhs >> d;
if (lhs) {
rhs.assign(n, d);
}
return lhs;
}
std::basic_istream<charT, Traits>&
operator>>(std::basic_istream<charT, Traits>& in,
token_matcher<charT, Traits, Allocator> matcher)
{
typename std::basic_string<charT, Traits, Allocator>::iterator
i = matcher.token.begin(),
end = matcher.token.end();
typename std::basic_istream<charT, Traits>::char_type c;
for (; i != end && in.get(c); ++i)
{
if (*i != c)
{
in.clear(std::basic_ios<charT, Traits>::failbit);
break;
}
}
return in;
}
void use_byte_order_mark (
std::basic_istream <codepoint, char_traits <codepoint> > & stream)
{
std::fpos<utf_mbstate> original_position = stream.tellg ();
if (!stream.good())
{
imbue_default (stream);
return;
}
try
{
stream.imbue (std::locale (stream.getloc(), new trivial_codecvt));
/*
We now start looking for a byte order mark.
The following must be recognised:
00 00 FE FF: UTF-32BE
FF FE 00 00: UTF-32LE
FE FF: UTF-16BE
FF FE: UTF-16LE
EF BB BF: UTF-8
*/
codepoint byte = stream.rdbuf()->sbumpc();
switch (byte)
{
case 0x00:
if (stream.rdbuf()->sbumpc() == 0x00 &&
stream.rdbuf()->sbumpc() == 0xfe &&
stream.rdbuf()->sbumpc() == 0xff)
{
imbue_and_eat_bom (stream, original_position,
new utf32be_codecvt);
return;
}
break;
case 0xef:
if (stream.rdbuf()->sbumpc() == 0xbb &&
stream.rdbuf()->sbumpc() == 0xbf)
{
imbue_and_eat_bom (stream, original_position,
new utf8_codecvt);
return;
}
break;
case 0xfe:
if (stream.rdbuf()->sbumpc() == 0xff)
{
imbue_and_eat_bom (stream, original_position,
new utf16be_codecvt);
return;
}
break;
case 0xff:
if (stream.rdbuf()->sbumpc() == 0xfe)
{
// This is either UTF-16LE or UTF-32LE.
if (stream.rdbuf()->sbumpc() == 0x00 &&
stream.rdbuf()->sbumpc() == 0x00)
{
imbue_and_eat_bom (stream, original_position,
new utf32le_codecvt);
} else
{
imbue_and_eat_bom (stream, original_position,
new utf16le_codecvt);
}
return;
}
break;
}
}
// If anything has gone wrong, just return to the original position and
// state and imbue the default codecvt.
catch (std::ios_base::failure &)
{}
stream.seekg (original_position);
stream.clear();
imbue_default (stream);
}
