Function ParseSimpleVersion

Source/cmPackageInfoReader.cxx:410–464

}

cm::optional<cmPackageInfoReader::Pep440Version> ParseSimpleVersion(
  std::string const& version)
{
  if (version.empty()) {
    return cm::nullopt;
  }

  cmPackageInfoReader::Pep440Version result;
  result.Simple = true;

  cm::string_view remnant{ version };
  for (;;) {
    // Find the next part separator.
    std::string::size_type const n = remnant.find_first_of(".+-"_s);
    if (n == 0) {
      // The part is an empty string.
      return cm::nullopt;
    }

    // Extract the part as a number.
    cm::string_view const part = remnant.substr(0, n);
    std::string::size_type const l = part.size();
    std::string::size_type p;
    unsigned long const value = std::stoul(std::string{ part }, &p);
    if (p != l || value > std::numeric_limits<unsigned>::max()) {
      // The part was not a valid number or is too big.
      return cm::nullopt;
    }
    result.ReleaseComponents.push_back(static_cast<unsigned>(value));

    // Have we consumed the entire input?
    if (n == std::string::npos) {
      return { std::move(result) };
    }

    // Lop off the current part.
    char const sep = remnant[n];
    remnant = remnant.substr(n + 1);
    if (sep == '+' || sep == '-') {
      // If we hit the local label, we're done.
      result.LocalLabel = remnant;
      return { std::move(result) };
    }

    // We just consumed a '.'; check that there's more.
    if (remnant.empty()) {
      // A trailing part separator is not allowed.
      return cm::nullopt;
    }

    // Continue with the remaining input.
  }

  // Unreachable.
}

} // namespace