C++ turn a std::tuple<char, char, char> into a std::string?

I am writing a lightweight parser combinator library (akin to Boost::Spirit) as hobby project.

One thing I’d like to do, is to automatically be able to convert a Result<std::tuple<char>>, Result<std::tuple<char, char>>, etc. into a std::string.

And similarly, if having e.g. a Result<std::tuple<int, int>> I’d like to be able to convert it to a Result<std::vector<int>> or more generally for any tuple containing zero or more elements of the same type T I’d like to be able to convert it automatically to a Result<Container<T>>.

How does one tackle something like this? I attempted for instance:

  template<typename Container>
  Result<decltype(std::make_from_tuple<Container>(std::declval<T>()))> () const {
      Result{Container{std::make_from_tuple<std::initializer_list<typename std::tuple_element<0, T>::type>> (std::get<T>(*this))}};
  }

but this does not work, as it turns out that it’s not possible to create an initializer list programmatically like this.

Source: Windows Questions C++

LEAVE A COMMENT