shadedtriangle

  using FormatArg = variant<int, float, string>;
  string FormatArgs(const char* fmt, const vector<FormatArg> &args);
  
  template <typename... Args>
  string Format(const char* fmt, Args&&... args) {
    vector<FormatArg> expanded_args = {args...};
    return FormatArgs(fmt, expanded_args);
  }

  int main() {
    cout << Format("Hello {} pi {}", "world", 3.14f);
  }

    for (auto& [key, value] : persons)