Function fastfloat_strncasecmp

app/src/ThirdParty/fast_float.h:525–563

// Compares two ASCII strings in a case insensitive manner.
template <typename UC>
inline FASTFLOAT_CONSTEXPR14 bool
fastfloat_strncasecmp(UC const *actual_mixedcase, UC const *expected_lowercase,
                      size_t length) {
  uint64_t mask{0};
  FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 1) { mask = 0x2020202020202020; }
  else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 2) {
    mask = 0x0020002000200020;
  }
  else FASTFLOAT_IF_CONSTEXPR17(sizeof(UC) == 4) {
    mask = 0x0000002000000020;
  }
  else {
    return false;
  }

  if (cpp20_and_in_constexpr()) {
    for (size_t i = 0; i < length; i++) {
      if ((actual_mixedcase[i] | 32) != expected_lowercase[i]) {
        return false;
      }
    }
    return true;
  } else {
    uint64_t val1{0}, val2{0};
    size_t sz{8 / (sizeof(UC))};
    for (size_t i = 0; i < length; i += sz) {
      val1 = val2 = 0;
      sz = sz < (length - i) ? sz : length - i;
      ::memcpy(&val1, actual_mixedcase + i, sz * sizeof(UC));
      ::memcpy(&val2, expected_lowercase + i, sz * sizeof(UC));
      val1 |= mask;
      val2 |= mask;
      if (val1 != val2) {
        return false;
      }
    }
    return true;
  }
}

#ifndef FLT_EVAL_METHOD
#error "FLT_EVAL_METHOD should be defined, please include cfloat."