Class String

visage_utils/string_utils.h:28–403

namespace visage {
  class String {
  public:
    template<typename Utf32String>
    static Utf32String convertUtf8ToUtf32(const std::string& utf8_str) {
      Utf32String result;
      result.reserve(utf8_str.size());

      for (size_t i = 0; i < utf8_str.size(); ++i) {
        unsigned char ch = utf8_str[i];

        if (ch < 0x80)  // ASCII character
          result.push_back(ch);
        else if (ch < 0xC0)  // Error on continuation byte
          result.push_back('*');
        else if (ch < 0xE0) {  // 2 byte character
          if (i + 1 >= utf8_str.size())  // Error - unfinished character.
            return result;

          result.push_back(((ch & 0x1F) << 6) | (utf8_str[i + 1] & 0x3F));
          i += 1;
        }
        else if (ch < 0xF0) {  // 3 byte character
          if (i + 2 >= utf8_str.size())  // Error - unfinished character.
            return result;

          result.push_back(((ch & 0x0F) << 12) | ((utf8_str[i + 1] & 0x3F) << 6) |
                           (utf8_str[i + 2] & 0x3F));
          i += 2;
        }
        else if (ch < 0xF8) {  // 4 byte character
          if (i + 3 >= utf8_str.size())  // Error - unfinished character.
            return result;

          result.push_back(((ch & 0x07) << 18) | ((utf8_str[i + 1] & 0x3F) << 12) |
                           ((utf8_str[i + 2] & 0x3F) << 6) | (utf8_str[i + 3] & 0x3F));
          i += 3;
        }
        else  // Error
          return result;
      }

      return result;
    }

    template<typename Utf32String>
    static std::string convertUtf32ToUtf8(const Utf32String& utf32_str) {
      std::string result;
      result.reserve(utf32_str.size() * 4);

      for (auto character : utf32_str) {
        if (character < 0x80)  // ASCII character
          result.push_back(static_cast<char>(character));
        else if (character < 0x800) {  // 2 byte character
          result.push_back(static_cast<char>((character >> 6) | 0xC0));
          result.push_back(static_cast<char>((character & 0x3F) | 0x80));
        }
        else if (character < 0x10000) {  // 3 byte character
          result.push_back(static_cast<char>((character >> 12) | 0xE0));