expect(..) could return the value instead of void

[tarcisiofischer]

As in rust, would be nice if expect(...) would return the value instead of void, so that I could make things like

auto val = func().expect("Unexpected return value case");

AFAIK, the way of doing this today is to do this instead:

auto result = func();
assert(!result.has_error());
auto val = result.value();

Implementation

I didn't test, but I guess would be something like the code below. Inspired but the current code

template <typename T, typename E>
template <typename String, typename>
inline RESULT_CPP14_CONSTEXPR
auto RESULT_NS_IMPL::result<T,E>::expect(String&& message)
  && -> typename std::add_lvalue_reference<T>::type
{
  if (has_error()) {
    detail::throw_bad_result_access_message(
      detail::forward<String>(message),
      static_cast<E&&>(m_storage.storage.m_error)
    );
  }
  return m_storage.storage.m_value;
}

Please let me know if this makes sense.

[bitwizeshift]

Hi @tarcisiofischer, thank you for the suggestion; this seems like a reasonable improvement.

Funny thing is that I modeled a lot of result's implementation after Rust, so it's weird that I didn't realize expect returns a reference to the object. 🤦‍♂️