in lib/yamlcpp/src/emitterutils.cpp [90:132]
bool GetNextCodePointAndAdvance(int& codePoint,
std::string::const_iterator& first,
std::string::const_iterator last) {
if (first == last)
return false;
int nBytes = Utf8BytesIndicated(*first);
if (nBytes < 1) {
// Bad lead byte
++first;
codePoint = REPLACEMENT_CHARACTER;
return true;
}
if (nBytes == 1) {
codePoint = *first++;
return true;
}
// Gather bits from trailing bytes
codePoint = static_cast<unsigned char>(*first) & ~(0xFF << (7 - nBytes));
++first;
--nBytes;
for (; nBytes > 0; ++first, --nBytes) {
if ((first == last) || !IsTrailingByte(*first)) {
codePoint = REPLACEMENT_CHARACTER;
break;
}
codePoint <<= 6;
codePoint |= *first & 0x3F;
}
// Check for illegal code points
if (codePoint > 0x10FFFF)
codePoint = REPLACEMENT_CHARACTER;
else if (codePoint >= 0xD800 && codePoint <= 0xDFFF)
codePoint = REPLACEMENT_CHARACTER;
else if ((codePoint & 0xFFFE) == 0xFFFE)
codePoint = REPLACEMENT_CHARACTER;
else if (codePoint >= 0xFDD0 && codePoint <= 0xFDEF)
codePoint = REPLACEMENT_CHARACTER;
return true;
}