Function ContainsUnprintableControlCodes

tests/gtest/gtest-all.cc:11464–11481

namespace {

bool ContainsUnprintableControlCodes(const char* str, size_t length) {
  const unsigned char *s = reinterpret_cast<const unsigned char *>(str);

  for (size_t i = 0; i < length; i++) {
    unsigned char ch = *s++;
    if (std::iscntrl(ch)) {
        switch (ch) {
        case '\t':
        case '\n':
        case '\r':
          break;
        default:
          return true;
        }
      }
  }
  return false;
}

bool IsUTF8TrailByte(unsigned char t) { return 0x80 <= t && t<= 0xbf; }