Method removeCharacters

visage_utils/string_utils.cpp:106–111

  }

  String String::removeCharacters(const String& characters) const {
    std::u32string result = string_;
    auto filter = [&characters](char32_t c) { return characters.find(c) != std::u32string::npos; };
    result.erase(std::remove_if(result.begin(), result.end(), filter), result.end());
    return result;
  }

  String String::removeEmojiVariations() const {
    std::u32string result = string_;