diff --git a/.gitignore b/.gitignore
index e88c330..6cb35a1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@ snippets/*
 subprojects/*/
 .vscode/ipch/*
 .vscode/settings.json
+benchmark/tl/*
diff --git a/benchmark/tl/expected.hpp b/benchmark/tl/expected.hpp
deleted file mode 100644
index 31a5193..0000000
--- a/benchmark/tl/expected.hpp
+++ /dev/null
@@ -1,2326 +0,0 @@
-///
-// expected - An implementation of std::expected with extensions
-// Written in 2017 by Simon Brand (simonrbrand@gmail.com, @TartanLlama)
-//
-// Documentation available at http://tl.tartanllama.xyz/
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to the
-// public domain worldwide. This software is distributed without any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software. If not, see
-// <http://creativecommons.org/publicdomain/zero/1.0/>.
-///
-
-#ifndef TL_EXPECTED_HPP
-#define TL_EXPECTED_HPP
-
-#define TL_EXPECTED_VERSION_MAJOR 1
-#define TL_EXPECTED_VERSION_MINOR 0
-#define TL_EXPECTED_VERSION_PATCH 1
-
-#include <exception>
-#include <functional>
-#include <type_traits>
-#include <utility>
-
-#if defined(__EXCEPTIONS) || defined(_CPPUNWIND)
-#define TL_EXPECTED_EXCEPTIONS_ENABLED
-#endif
-
-#if (defined(_MSC_VER) && _MSC_VER == 1900)
-#define TL_EXPECTED_MSVC2015
-#define TL_EXPECTED_MSVC2015_CONSTEXPR
-#else
-#define TL_EXPECTED_MSVC2015_CONSTEXPR constexpr
-#endif
-
-#if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 &&              \
-     !defined(__clang__))
-#define TL_EXPECTED_GCC49
-#endif
-
-#if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 4 &&              \
-     !defined(__clang__))
-#define TL_EXPECTED_GCC54
-#endif
-
-#if (defined(__GNUC__) && __GNUC__ == 5 && __GNUC_MINOR__ <= 5 &&              \
-     !defined(__clang__))
-#define TL_EXPECTED_GCC55
-#endif
-
-#if (defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ <= 9 &&              \
-     !defined(__clang__))
-// GCC < 5 doesn't support overloading on const&& for member functions
-
-#define TL_EXPECTED_NO_CONSTRR
-// GCC < 5 doesn't support some standard C++11 type traits
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)                         \
-  std::has_trivial_copy_constructor<T>
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T)                            \
-  std::has_trivial_copy_assign<T>
-
-// This one will be different for GCC 5.7 if it's ever supported
-#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T)                               \
-  std::is_trivially_destructible<T>
-
-// GCC 5 < v < 8 has a bug in is_trivially_copy_constructible which breaks std::vector
-// for non-copyable types
-#elif (defined(__GNUC__) && __GNUC__ < 8 &&                                                \
-     !defined(__clang__))
-#ifndef TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX
-#define TL_GCC_LESS_8_TRIVIALLY_COPY_CONSTRUCTIBLE_MUTEX
-namespace tl {
-  namespace detail {
-      template<class T>
-      struct is_trivially_copy_constructible : std::is_trivially_copy_constructible<T>{};
-#ifdef _GLIBCXX_VECTOR
-      template<class T, class A>
-      struct is_trivially_copy_constructible<std::vector<T,A>>
-          : std::false_type{};
-#endif
-  }
-}
-#endif
-
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)                                     \
-  tl::detail::is_trivially_copy_constructible<T>
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T)                                        \
-  std::is_trivially_copy_assignable<T>
-#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T) std::is_trivially_destructible<T>
-#else
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)                         \
-  std::is_trivially_copy_constructible<T>
-#define TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T)                            \
-  std::is_trivially_copy_assignable<T>
-#define TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T)                               \
-  std::is_trivially_destructible<T>
-#endif
-
-#if __cplusplus > 201103L
-#define TL_EXPECTED_CXX14
-#endif
-
-#ifdef TL_EXPECTED_GCC49
-#define TL_EXPECTED_GCC49_CONSTEXPR
-#else
-#define TL_EXPECTED_GCC49_CONSTEXPR constexpr
-#endif
-
-#if (__cplusplus == 201103L || defined(TL_EXPECTED_MSVC2015) ||                \
-     defined(TL_EXPECTED_GCC49))
-#define TL_EXPECTED_11_CONSTEXPR
-#else
-#define TL_EXPECTED_11_CONSTEXPR constexpr
-#endif
-
-namespace tl {
-template <class T, class E> class expected;
-
-#ifndef TL_MONOSTATE_INPLACE_MUTEX
-#define TL_MONOSTATE_INPLACE_MUTEX
-class monostate {};
-
-struct in_place_t {
-  explicit in_place_t() = default;
-};
-static constexpr in_place_t in_place{};
-#endif
-
-template <class E> class unexpected {
-public:
-  static_assert(!std::is_same<E, void>::value, "E must not be void");
-
-  unexpected() = delete;
-  constexpr explicit unexpected(const E &e) : m_val(e) {}
-
-  constexpr explicit unexpected(E &&e) : m_val(std::move(e)) {}
-
-  constexpr const E &value() const & { return m_val; }
-  TL_EXPECTED_11_CONSTEXPR E &value() & { return m_val; }
-  TL_EXPECTED_11_CONSTEXPR E &&value() && { return std::move(m_val); }
-  constexpr const E &&value() const && { return std::move(m_val); }
-
-private:
-  E m_val;
-};
-
-template <class E>
-constexpr bool operator==(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() == rhs.value();
-}
-template <class E>
-constexpr bool operator!=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() != rhs.value();
-}
-template <class E>
-constexpr bool operator<(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() < rhs.value();
-}
-template <class E>
-constexpr bool operator<=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() <= rhs.value();
-}
-template <class E>
-constexpr bool operator>(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() > rhs.value();
-}
-template <class E>
-constexpr bool operator>=(const unexpected<E> &lhs, const unexpected<E> &rhs) {
-  return lhs.value() >= rhs.value();
-}
-
-template <class E>
-unexpected<typename std::decay<E>::type> make_unexpected(E &&e) {
-  return unexpected<typename std::decay<E>::type>(std::forward<E>(e));
-}
-
-struct unexpect_t {
-  unexpect_t() = default;
-};
-static constexpr unexpect_t unexpect{};
-
-namespace detail {
-template<typename E>
-[[noreturn]] TL_EXPECTED_11_CONSTEXPR void throw_exception(E &&e) {
-#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-    throw std::forward<E>(e);
-#else
-  #ifdef _MSC_VER
-    __assume(0);
-  #else
-    __builtin_unreachable();
-  #endif
-#endif
-}
-
-#ifndef TL_TRAITS_MUTEX
-#define TL_TRAITS_MUTEX
-// C++14-style aliases for brevity
-template <class T> using remove_const_t = typename std::remove_const<T>::type;
-template <class T>
-using remove_reference_t = typename std::remove_reference<T>::type;
-template <class T> using decay_t = typename std::decay<T>::type;
-template <bool E, class T = void>
-using enable_if_t = typename std::enable_if<E, T>::type;
-template <bool B, class T, class F>
-using conditional_t = typename std::conditional<B, T, F>::type;
-
-// std::conjunction from C++17
-template <class...> struct conjunction : std::true_type {};
-template <class B> struct conjunction<B> : B {};
-template <class B, class... Bs>
-struct conjunction<B, Bs...>
-  : std::conditional<bool(B::value), conjunction<Bs...>, B>::type {};
-
-#if defined(_LIBCPP_VERSION) && __cplusplus == 201103L
-#define TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
-#endif
-
-// In C++11 mode, there's an issue in libc++'s std::mem_fn
-// which results in a hard-error when using it in a noexcept expression
-// in some cases. This is a check to workaround the common failing case.
-#ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
-template <class T> struct is_pointer_to_non_const_member_func : std::false_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...)> : std::true_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...)&> : std::true_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) &&> : std::true_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile> : std::true_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile &> : std::true_type {};
-template <class T, class Ret, class... Args>
-struct is_pointer_to_non_const_member_func<Ret(T::*) (Args...) volatile &&> : std::true_type {};
-
-template <class T> struct is_const_or_const_ref : std::false_type {};
-template <class T> struct is_const_or_const_ref<T const&> : std::true_type {};
-template <class T> struct is_const_or_const_ref<T const> : std::true_type {};
-#endif
-
-// std::invoke from C++17
-// https://stackoverflow.com/questions/38288042/c11-14-invoke-workaround
-template <typename Fn, typename... Args,
-#ifdef TL_TRAITS_LIBCXX_MEM_FN_WORKAROUND
-  typename = enable_if_t<!(is_pointer_to_non_const_member_func<Fn>::value
-    && is_const_or_const_ref<Args...>::value)>,
-#endif
-  typename = enable_if_t<std::is_member_pointer<decay_t<Fn>>::value>,
-  int = 0>
-  constexpr auto invoke(Fn && f, Args && ... args) noexcept(
-    noexcept(std::mem_fn(f)(std::forward<Args>(args)...)))
-  -> decltype(std::mem_fn(f)(std::forward<Args>(args)...)) {
-  return std::mem_fn(f)(std::forward<Args>(args)...);
-}
-
-template <typename Fn, typename... Args,
-  typename = enable_if_t<!std::is_member_pointer<decay_t<Fn>>::value>>
-  constexpr auto invoke(Fn && f, Args && ... args) noexcept(
-    noexcept(std::forward<Fn>(f)(std::forward<Args>(args)...)))
-  -> decltype(std::forward<Fn>(f)(std::forward<Args>(args)...)) {
-  return std::forward<Fn>(f)(std::forward<Args>(args)...);
-}
-
-// std::invoke_result from C++17
-template <class F, class, class... Us> struct invoke_result_impl;
-
-template <class F, class... Us>
-struct invoke_result_impl<
-  F, decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...), void()),
-  Us...> {
-  using type = decltype(detail::invoke(std::declval<F>(), std::declval<Us>()...));
-};
-
-template <class F, class... Us>
-using invoke_result = invoke_result_impl<F, void, Us...>;
-
-template <class F, class... Us>
-using invoke_result_t = typename invoke_result<F, Us...>::type;
-
-#if defined(_MSC_VER) && _MSC_VER <= 1900
-// TODO make a version which works with MSVC 2015
-template <class T, class U = T> struct is_swappable : std::true_type {};
-
-template <class T, class U = T> struct is_nothrow_swappable : std::true_type {};
-#else
-// https://stackoverflow.com/questions/26744589/what-is-a-proper-way-to-implement-is-swappable-to-test-for-the-swappable-concept
-namespace swap_adl_tests {
-  // if swap ADL finds this then it would call std::swap otherwise (same
-  // signature)
-  struct tag {};
-
-  template <class T> tag swap(T&, T&);
-  template <class T, std::size_t N> tag swap(T(&a)[N], T(&b)[N]);
-
-  // helper functions to test if an unqualified swap is possible, and if it
-  // becomes std::swap
-  template <class, class> std::false_type can_swap(...) noexcept(false);
-  template <class T, class U,
-    class = decltype(swap(std::declval<T&>(), std::declval<U&>()))>
-    std::true_type can_swap(int) noexcept(noexcept(swap(std::declval<T&>(),
-      std::declval<U&>())));
-
-  template <class, class> std::false_type uses_std(...);
-  template <class T, class U>
-  std::is_same<decltype(swap(std::declval<T&>(), std::declval<U&>())), tag>
-    uses_std(int);
-
-  template <class T>
-  struct is_std_swap_noexcept
-    : std::integral_constant<bool,
-    std::is_nothrow_move_constructible<T>::value&&
-    std::is_nothrow_move_assignable<T>::value> {};
-
-  template <class T, std::size_t N>
-  struct is_std_swap_noexcept<T[N]> : is_std_swap_noexcept<T> {};
-
-  template <class T, class U>
-  struct is_adl_swap_noexcept
-    : std::integral_constant<bool, noexcept(can_swap<T, U>(0))> {};
-} // namespace swap_adl_tests
-
-template <class T, class U = T>
-struct is_swappable
-  : std::integral_constant<
-  bool,
-  decltype(detail::swap_adl_tests::can_swap<T, U>(0))::value &&
-  (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value ||
-  (std::is_move_assignable<T>::value &&
-    std::is_move_constructible<T>::value))> {};
-
-template <class T, std::size_t N>
-struct is_swappable<T[N], T[N]>
-  : std::integral_constant<
-  bool,
-  decltype(detail::swap_adl_tests::can_swap<T[N], T[N]>(0))::value &&
-  (!decltype(
-    detail::swap_adl_tests::uses_std<T[N], T[N]>(0))::value ||
-    is_swappable<T, T>::value)> {};
-
-template <class T, class U = T>
-struct is_nothrow_swappable
-  : std::integral_constant<
-  bool,
-  is_swappable<T, U>::value &&
-  ((decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value
-    && detail::swap_adl_tests::is_std_swap_noexcept<T>::value) ||
-    (!decltype(detail::swap_adl_tests::uses_std<T, U>(0))::value &&
-      detail::swap_adl_tests::is_adl_swap_noexcept<T,
-      U>::value))> {
-};
-#endif
-#endif
-
-// Trait for checking if a type is a tl::expected
-template <class T> struct is_expected_impl : std::false_type {};
-template <class T, class E>
-struct is_expected_impl<expected<T, E>> : std::true_type {};
-template <class T> using is_expected = is_expected_impl<decay_t<T>>;
-
-template <class T, class E, class U>
-using expected_enable_forward_value = detail::enable_if_t<
-    std::is_constructible<T, U &&>::value &&
-    !std::is_same<detail::decay_t<U>, in_place_t>::value &&
-    !std::is_same<expected<T, E>, detail::decay_t<U>>::value &&
-    !std::is_same<unexpected<E>, detail::decay_t<U>>::value>;
-
-template <class T, class E, class U, class G, class UR, class GR>
-using expected_enable_from_other = detail::enable_if_t<
-    std::is_constructible<T, UR>::value &&
-    std::is_constructible<E, GR>::value &&
-    !std::is_constructible<T, expected<U, G> &>::value &&
-    !std::is_constructible<T, expected<U, G> &&>::value &&
-    !std::is_constructible<T, const expected<U, G> &>::value &&
-    !std::is_constructible<T, const expected<U, G> &&>::value &&
-    !std::is_convertible<expected<U, G> &, T>::value &&
-    !std::is_convertible<expected<U, G> &&, T>::value &&
-    !std::is_convertible<const expected<U, G> &, T>::value &&
-    !std::is_convertible<const expected<U, G> &&, T>::value>;
-
-template <class T, class U>
-using is_void_or = conditional_t<std::is_void<T>::value, std::true_type, U>;
-
-template <class T>
-using is_copy_constructible_or_void =
-    is_void_or<T, std::is_copy_constructible<T>>;
-
-template <class T>
-using is_move_constructible_or_void =
-    is_void_or<T, std::is_move_constructible<T>>;
-
-template <class T>
-using is_copy_assignable_or_void =
-    is_void_or<T, std::is_copy_assignable<T>>;
-
-
-template <class T>
-using is_move_assignable_or_void =
-    is_void_or<T, std::is_move_assignable<T>>;
-    
-
-} // namespace detail
-
-namespace detail {
-struct no_init_t {};
-static constexpr no_init_t no_init{};
-
-// Implements the storage of the values, and ensures that the destructor is
-// trivial if it can be.
-//
-// This specialization is for where neither `T` or `E` is trivially
-// destructible, so the destructors must be called on destruction of the
-// `expected`
-template <class T, class E, bool = std::is_trivially_destructible<T>::value,
-          bool = std::is_trivially_destructible<E>::value>
-struct expected_storage_base {
-  constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {}
-  constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * =
-                nullptr>
-  constexpr expected_storage_base(in_place_t, Args &&... args)
-      : m_val(std::forward<Args>(args)...), m_has_val(true) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr expected_storage_base(in_place_t, std::initializer_list<U> il,
-                                  Args &&... args)
-      : m_val(il, std::forward<Args>(args)...), m_has_val(true) {}
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() {
-    if (m_has_val) {
-      m_val.~T();
-    } else {
-      m_unexpect.~unexpected<E>();
-    }
-  }
-  union {
-    T m_val;
-    unexpected<E> m_unexpect;
-    char m_no_init;
-  };
-  bool m_has_val;
-};
-
-// This specialization is for when both `T` and `E` are trivially-destructible,
-// so the destructor of the `expected` can be trivial.
-template <class T, class E> struct expected_storage_base<T, E, true, true> {
-  constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {}
-  constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * =
-                nullptr>
-  constexpr expected_storage_base(in_place_t, Args &&... args)
-      : m_val(std::forward<Args>(args)...), m_has_val(true) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr expected_storage_base(in_place_t, std::initializer_list<U> il,
-                                  Args &&... args)
-      : m_val(il, std::forward<Args>(args)...), m_has_val(true) {}
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() = default;
-  union {
-    T m_val;
-    unexpected<E> m_unexpect;
-    char m_no_init;
-  };
-  bool m_has_val;
-};
-
-// T is trivial, E is not.
-template <class T, class E> struct expected_storage_base<T, E, true, false> {
-  constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {}
-  TL_EXPECTED_MSVC2015_CONSTEXPR expected_storage_base(no_init_t)
-      : m_no_init(), m_has_val(false) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * =
-                nullptr>
-  constexpr expected_storage_base(in_place_t, Args &&... args)
-      : m_val(std::forward<Args>(args)...), m_has_val(true) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr expected_storage_base(in_place_t, std::initializer_list<U> il,
-                                  Args &&... args)
-      : m_val(il, std::forward<Args>(args)...), m_has_val(true) {}
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() {
-    if (!m_has_val) {
-      m_unexpect.~unexpected<E>();
-    }
-  }
-
-  union {
-    T m_val;
-    unexpected<E> m_unexpect;
-    char m_no_init;
-  };
-  bool m_has_val;
-};
-
-// E is trivial, T is not.
-template <class T, class E> struct expected_storage_base<T, E, false, true> {
-  constexpr expected_storage_base() : m_val(T{}), m_has_val(true) {}
-  constexpr expected_storage_base(no_init_t) : m_no_init(), m_has_val(false) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * =
-                nullptr>
-  constexpr expected_storage_base(in_place_t, Args &&... args)
-      : m_val(std::forward<Args>(args)...), m_has_val(true) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr expected_storage_base(in_place_t, std::initializer_list<U> il,
-                                  Args &&... args)
-      : m_val(il, std::forward<Args>(args)...), m_has_val(true) {}
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() {
-    if (m_has_val) {
-      m_val.~T();
-    }
-  }
-  union {
-    T m_val;
-    unexpected<E> m_unexpect;
-    char m_no_init;
-  };
-  bool m_has_val;
-};
-
-// `T` is `void`, `E` is trivially-destructible
-template <class E> struct expected_storage_base<void, E, false, true> {
-  TL_EXPECTED_MSVC2015_CONSTEXPR expected_storage_base() : m_has_val(true) {}
-  constexpr expected_storage_base(no_init_t) : m_val(), m_has_val(false) {}
-
-  constexpr expected_storage_base(in_place_t) : m_has_val(true) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() = default;
-  struct dummy {};
-  union {
-    unexpected<E> m_unexpect;
-    dummy m_val;
-  };
-  bool m_has_val;
-};
-
-// `T` is `void`, `E` is not trivially-destructible
-template <class E> struct expected_storage_base<void, E, false, false> {
-  constexpr expected_storage_base() : m_dummy(), m_has_val(true) {}
-  constexpr expected_storage_base(no_init_t) : m_dummy(), m_has_val(false) {}
-
-  constexpr expected_storage_base(in_place_t) : m_dummy(), m_has_val(true) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected_storage_base(unexpect_t, Args &&... args)
-      : m_unexpect(std::forward<Args>(args)...), m_has_val(false) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected_storage_base(unexpect_t,
-                                           std::initializer_list<U> il,
-                                           Args &&... args)
-      : m_unexpect(il, std::forward<Args>(args)...), m_has_val(false) {}
-
-  ~expected_storage_base() {
-    if (!m_has_val) {
-      m_unexpect.~unexpected<E>();
-    }
-  }
-
-  union {
-    unexpected<E> m_unexpect;
-    char m_dummy;
-  };
-  bool m_has_val;
-};
-
-// This base class provides some handy member functions which can be used in
-// further derived classes
-template <class T, class E>
-struct expected_operations_base : expected_storage_base<T, E> {
-  using expected_storage_base<T, E>::expected_storage_base;
-
-  template <class... Args> void construct(Args &&... args) noexcept {
-    new (std::addressof(this->m_val)) T(std::forward<Args>(args)...);
-    this->m_has_val = true;
-  }
-
-  template <class Rhs> void construct_with(Rhs &&rhs) noexcept {
-    new (std::addressof(this->m_val)) T(std::forward<Rhs>(rhs).get());
-    this->m_has_val = true;
-  }
-
-  template <class... Args> void construct_error(Args &&... args) noexcept {
-    new (std::addressof(this->m_unexpect))
-        unexpected<E>(std::forward<Args>(args)...);
-    this->m_has_val = false;
-  }
-
-  #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-
-  // These assign overloads ensure that the most efficient assignment
-  // implementation is used while maintaining the strong exception guarantee.
-  // The problematic case is where rhs has a value, but *this does not.
-  //
-  // This overload handles the case where we can just copy-construct `T`
-  // directly into place without throwing.
-  template <class U = T,
-            detail::enable_if_t<std::is_nothrow_copy_constructible<U>::value>
-                * = nullptr>
-  void assign(const expected_operations_base &rhs) noexcept {
-    if (!this->m_has_val && rhs.m_has_val) {
-      geterr().~unexpected<E>();
-      construct(rhs.get());
-    } else {
-      assign_common(rhs);
-    }
-  }
-
-  // This overload handles the case where we can attempt to create a copy of
-  // `T`, then no-throw move it into place if the copy was successful.
-  template <class U = T,
-            detail::enable_if_t<!std::is_nothrow_copy_constructible<U>::value &&
-                                std::is_nothrow_move_constructible<U>::value>
-                * = nullptr>
-  void assign(const expected_operations_base &rhs) noexcept {
-    if (!this->m_has_val && rhs.m_has_val) {
-      T tmp = rhs.get();
-      geterr().~unexpected<E>();
-      construct(std::move(tmp));
-    } else {
-      assign_common(rhs);
-    }
-  }
-
-  // This overload is the worst-case, where we have to move-construct the
-  // unexpected value into temporary storage, then try to copy the T into place.
-  // If the construction succeeds, then everything is fine, but if it throws,
-  // then we move the old unexpected value back into place before rethrowing the
-  // exception.
-  template <class U = T,
-            detail::enable_if_t<!std::is_nothrow_copy_constructible<U>::value &&
-                                !std::is_nothrow_move_constructible<U>::value>
-                * = nullptr>
-  void assign(const expected_operations_base &rhs) {
-    if (!this->m_has_val && rhs.m_has_val) {
-      auto tmp = std::move(geterr());
-      geterr().~unexpected<E>();
-
-#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-      try {
-        construct(rhs.get());
-      } catch (...) {
-        geterr() = std::move(tmp);
-        throw;
-      }
-#else
-      construct(rhs.get());
-#endif
-    } else {
-      assign_common(rhs);
-    }
-  }
-
-  // These overloads do the same as above, but for rvalues
-  template <class U = T,
-            detail::enable_if_t<std::is_nothrow_move_constructible<U>::value>
-                * = nullptr>
-  void assign(expected_operations_base &&rhs) noexcept {
-    if (!this->m_has_val && rhs.m_has_val) {
-      geterr().~unexpected<E>();
-      construct(std::move(rhs).get());
-    } else {
-      assign_common(std::move(rhs));
-    }
-  }
-
-  template <class U = T,
-            detail::enable_if_t<!std::is_nothrow_move_constructible<U>::value>
-                * = nullptr>
-  void assign(expected_operations_base &&rhs) {
-    if (!this->m_has_val && rhs.m_has_val) {
-      auto tmp = std::move(geterr());
-      geterr().~unexpected<E>();
-#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-      try {
-        construct(std::move(rhs).get());
-      } catch (...) {
-        geterr() = std::move(tmp);
-        throw;
-      }
-#else
-      construct(std::move(rhs).get());
-#endif
-    } else {
-      assign_common(std::move(rhs));
-    }
-  }
-
-  #else
-
-  // If exceptions are disabled then we can just copy-construct
-  void assign(const expected_operations_base &rhs) noexcept {
-    if (!this->m_has_val && rhs.m_has_val) {
-      geterr().~unexpected<E>();
-      construct(rhs.get());
-    } else {
-      assign_common(rhs);
-    }
-  }
-
-  void assign(expected_operations_base &&rhs) noexcept {
-    if (!this->m_has_val && rhs.m_has_val) {
-      geterr().~unexpected<E>();
-      construct(std::move(rhs).get());
-    } else {
-      assign_common(rhs);
-    }
-  }
-
-  #endif
-
-  // The common part of move/copy assigning
-  template <class Rhs> void assign_common(Rhs &&rhs) {
-    if (this->m_has_val) {
-      if (rhs.m_has_val) {
-        get() = std::forward<Rhs>(rhs).get();
-      } else {
-		destroy_val();
-        construct_error(std::forward<Rhs>(rhs).geterr());
-      }
-    } else {
-      if (!rhs.m_has_val) {
-        geterr() = std::forward<Rhs>(rhs).geterr();
-      }
-    }
-  }
-
-  bool has_value() const { return this->m_has_val; }
-
-  TL_EXPECTED_11_CONSTEXPR T &get() & { return this->m_val; }
-  constexpr const T &get() const & { return this->m_val; }
-  TL_EXPECTED_11_CONSTEXPR T &&get() && { return std::move(this->m_val); }
-#ifndef TL_EXPECTED_NO_CONSTRR
-  constexpr const T &&get() const && { return std::move(this->m_val); }
-#endif
-
-  TL_EXPECTED_11_CONSTEXPR unexpected<E> &geterr() & {
-    return this->m_unexpect;
-  }
-  constexpr const unexpected<E> &geterr() const & { return this->m_unexpect; }
-  TL_EXPECTED_11_CONSTEXPR unexpected<E> &&geterr() && {
-    return std::move(this->m_unexpect);
-  }
-#ifndef TL_EXPECTED_NO_CONSTRR
-  constexpr const unexpected<E> &&geterr() const && {
-    return std::move(this->m_unexpect);
-  }
-#endif
-
-  TL_EXPECTED_11_CONSTEXPR void destroy_val() {
-	get().~T();
-  }
-};
-
-// This base class provides some handy member functions which can be used in
-// further derived classes
-template <class E>
-struct expected_operations_base<void, E> : expected_storage_base<void, E> {
-  using expected_storage_base<void, E>::expected_storage_base;
-
-  template <class... Args> void construct() noexcept { this->m_has_val = true; }
-
-  // This function doesn't use its argument, but needs it so that code in
-  // levels above this can work independently of whether T is void
-  template <class Rhs> void construct_with(Rhs &&) noexcept {
-    this->m_has_val = true;
-  }
-
-  template <class... Args> void construct_error(Args &&... args) noexcept {
-    new (std::addressof(this->m_unexpect))
-        unexpected<E>(std::forward<Args>(args)...);
-    this->m_has_val = false;
-  }
-
-  template <class Rhs> void assign(Rhs &&rhs) noexcept {
-    if (!this->m_has_val) {
-      if (rhs.m_has_val) {
-        geterr().~unexpected<E>();
-        construct();
-      } else {
-        geterr() = std::forward<Rhs>(rhs).geterr();
-      }
-    } else {
-      if (!rhs.m_has_val) {
-        construct_error(std::forward<Rhs>(rhs).geterr());
-      }
-    }
-  }
-
-  bool has_value() const { return this->m_has_val; }
-
-  TL_EXPECTED_11_CONSTEXPR unexpected<E> &geterr() & {
-    return this->m_unexpect;
-  }
-  constexpr const unexpected<E> &geterr() const & { return this->m_unexpect; }
-  TL_EXPECTED_11_CONSTEXPR unexpected<E> &&geterr() && {
-    return std::move(this->m_unexpect);
-  }
-#ifndef TL_EXPECTED_NO_CONSTRR
-  constexpr const unexpected<E> &&geterr() const && {
-    return std::move(this->m_unexpect);
-  }
-#endif
-
-  TL_EXPECTED_11_CONSTEXPR void destroy_val() {
-	  //no-op
-  }
-};
-
-// This class manages conditionally having a trivial copy constructor
-// This specialization is for when T and E are trivially copy constructible
-template <class T, class E,
-          bool = is_void_or<T, TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T)>::
-              value &&TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(E)::value>
-struct expected_copy_base : expected_operations_base<T, E> {
-  using expected_operations_base<T, E>::expected_operations_base;
-};
-
-// This specialization is for when T or E are not trivially copy constructible
-template <class T, class E>
-struct expected_copy_base<T, E, false> : expected_operations_base<T, E> {
-  using expected_operations_base<T, E>::expected_operations_base;
-
-  expected_copy_base() = default;
-  expected_copy_base(const expected_copy_base &rhs)
-      : expected_operations_base<T, E>(no_init) {
-    if (rhs.has_value()) {
-      this->construct_with(rhs);
-    } else {
-      this->construct_error(rhs.geterr());
-    }
-  }
-
-  expected_copy_base(expected_copy_base &&rhs) = default;
-  expected_copy_base &operator=(const expected_copy_base &rhs) = default;
-  expected_copy_base &operator=(expected_copy_base &&rhs) = default;
-};
-
-// This class manages conditionally having a trivial move constructor
-// Unfortunately there's no way to achieve this in GCC < 5 AFAIK, since it
-// doesn't implement an analogue to std::is_trivially_move_constructible. We
-// have to make do with a non-trivial move constructor even if T is trivially
-// move constructible
-#ifndef TL_EXPECTED_GCC49
-template <class T, class E,
-          bool = is_void_or<T, std::is_trivially_move_constructible<T>>::value
-              &&std::is_trivially_move_constructible<E>::value>
-struct expected_move_base : expected_copy_base<T, E> {
-  using expected_copy_base<T, E>::expected_copy_base;
-};
-#else
-template <class T, class E, bool = false> struct expected_move_base;
-#endif
-template <class T, class E>
-struct expected_move_base<T, E, false> : expected_copy_base<T, E> {
-  using expected_copy_base<T, E>::expected_copy_base;
-
-  expected_move_base() = default;
-  expected_move_base(const expected_move_base &rhs) = default;
-
-  expected_move_base(expected_move_base &&rhs) noexcept(
-      std::is_nothrow_move_constructible<T>::value)
-      : expected_copy_base<T, E>(no_init) {
-    if (rhs.has_value()) {
-      this->construct_with(std::move(rhs));
-    } else {
-      this->construct_error(std::move(rhs.geterr()));
-    }
-  }
-  expected_move_base &operator=(const expected_move_base &rhs) = default;
-  expected_move_base &operator=(expected_move_base &&rhs) = default;
-};
-
-// This class manages conditionally having a trivial copy assignment operator
-template <class T, class E,
-          bool = is_void_or<
-              T, conjunction<TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(T),
-                             TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(T),
-                             TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(T)>>::value
-              &&TL_EXPECTED_IS_TRIVIALLY_COPY_ASSIGNABLE(E)::value
-                  &&TL_EXPECTED_IS_TRIVIALLY_COPY_CONSTRUCTIBLE(E)::value
-                      &&TL_EXPECTED_IS_TRIVIALLY_DESTRUCTIBLE(E)::value>
-struct expected_copy_assign_base : expected_move_base<T, E> {
-  using expected_move_base<T, E>::expected_move_base;
-};
-
-template <class T, class E>
-struct expected_copy_assign_base<T, E, false> : expected_move_base<T, E> {
-  using expected_move_base<T, E>::expected_move_base;
-
-  expected_copy_assign_base() = default;
-  expected_copy_assign_base(const expected_copy_assign_base &rhs) = default;
-
-  expected_copy_assign_base(expected_copy_assign_base &&rhs) = default;
-  expected_copy_assign_base &operator=(const expected_copy_assign_base &rhs) {
-    this->assign(rhs);
-    return *this;
-  }
-  expected_copy_assign_base &
-  operator=(expected_copy_assign_base &&rhs) = default;
-};
-
-// This class manages conditionally having a trivial move assignment operator
-// Unfortunately there's no way to achieve this in GCC < 5 AFAIK, since it
-// doesn't implement an analogue to std::is_trivially_move_assignable. We have
-// to make do with a non-trivial move assignment operator even if T is trivially
-// move assignable
-#ifndef TL_EXPECTED_GCC49
-template <class T, class E,
-          bool =
-              is_void_or<T, conjunction<std::is_trivially_destructible<T>,
-                                        std::is_trivially_move_constructible<T>,
-                                        std::is_trivially_move_assignable<T>>>::
-                  value &&std::is_trivially_destructible<E>::value
-                      &&std::is_trivially_move_constructible<E>::value
-                          &&std::is_trivially_move_assignable<E>::value>
-struct expected_move_assign_base : expected_copy_assign_base<T, E> {
-  using expected_copy_assign_base<T, E>::expected_copy_assign_base;
-};
-#else
-template <class T, class E, bool = false> struct expected_move_assign_base;
-#endif
-
-template <class T, class E>
-struct expected_move_assign_base<T, E, false>
-    : expected_copy_assign_base<T, E> {
-  using expected_copy_assign_base<T, E>::expected_copy_assign_base;
-
-  expected_move_assign_base() = default;
-  expected_move_assign_base(const expected_move_assign_base &rhs) = default;
-
-  expected_move_assign_base(expected_move_assign_base &&rhs) = default;
-
-  expected_move_assign_base &
-  operator=(const expected_move_assign_base &rhs) = default;
-
-  expected_move_assign_base &
-  operator=(expected_move_assign_base &&rhs) noexcept(
-      std::is_nothrow_move_constructible<T>::value
-          &&std::is_nothrow_move_assignable<T>::value) {
-    this->assign(std::move(rhs));
-    return *this;
-  }
-};
-
-// expected_delete_ctor_base will conditionally delete copy and move
-// constructors depending on whether T is copy/move constructible
-template <class T, class E,
-          bool EnableCopy = (is_copy_constructible_or_void<T>::value &&
-                             std::is_copy_constructible<E>::value),
-          bool EnableMove = (is_move_constructible_or_void<T>::value &&
-                             std::is_move_constructible<E>::value)>
-struct expected_delete_ctor_base {
-  expected_delete_ctor_base() = default;
-  expected_delete_ctor_base(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = default;
-  expected_delete_ctor_base &
-  operator=(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base &
-  operator=(expected_delete_ctor_base &&) noexcept = default;
-};
-
-template <class T, class E>
-struct expected_delete_ctor_base<T, E, true, false> {
-  expected_delete_ctor_base() = default;
-  expected_delete_ctor_base(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = delete;
-  expected_delete_ctor_base &
-  operator=(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base &
-  operator=(expected_delete_ctor_base &&) noexcept = default;
-};
-
-template <class T, class E>
-struct expected_delete_ctor_base<T, E, false, true> {
-  expected_delete_ctor_base() = default;
-  expected_delete_ctor_base(const expected_delete_ctor_base &) = delete;
-  expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = default;
-  expected_delete_ctor_base &
-  operator=(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base &
-  operator=(expected_delete_ctor_base &&) noexcept = default;
-};
-
-template <class T, class E>
-struct expected_delete_ctor_base<T, E, false, false> {
-  expected_delete_ctor_base() = default;
-  expected_delete_ctor_base(const expected_delete_ctor_base &) = delete;
-  expected_delete_ctor_base(expected_delete_ctor_base &&) noexcept = delete;
-  expected_delete_ctor_base &
-  operator=(const expected_delete_ctor_base &) = default;
-  expected_delete_ctor_base &
-  operator=(expected_delete_ctor_base &&) noexcept = default;
-};
-
-// expected_delete_assign_base will conditionally delete copy and move
-// constructors depending on whether T and E are copy/move constructible +
-// assignable
-template <class T, class E,
-          bool EnableCopy = (is_copy_constructible_or_void<T>::value &&
-                             std::is_copy_constructible<E>::value &&
-                             is_copy_assignable_or_void<T>::value &&
-                             std::is_copy_assignable<E>::value),
-          bool EnableMove = (is_move_constructible_or_void<T>::value &&
-                             std::is_move_constructible<E>::value &&
-                             is_move_assignable_or_void<T>::value &&
-                             std::is_move_assignable<E>::value)>
-struct expected_delete_assign_base {
-  expected_delete_assign_base() = default;
-  expected_delete_assign_base(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base(expected_delete_assign_base &&) noexcept =
-      default;
-  expected_delete_assign_base &
-  operator=(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base &
-  operator=(expected_delete_assign_base &&) noexcept = default;
-};
-
-template <class T, class E>
-struct expected_delete_assign_base<T, E, true, false> {
-  expected_delete_assign_base() = default;
-  expected_delete_assign_base(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base(expected_delete_assign_base &&) noexcept =
-      default;
-  expected_delete_assign_base &
-  operator=(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base &
-  operator=(expected_delete_assign_base &&) noexcept = delete;
-};
-
-template <class T, class E>
-struct expected_delete_assign_base<T, E, false, true> {
-  expected_delete_assign_base() = default;
-  expected_delete_assign_base(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base(expected_delete_assign_base &&) noexcept =
-      default;
-  expected_delete_assign_base &
-  operator=(const expected_delete_assign_base &) = delete;
-  expected_delete_assign_base &
-  operator=(expected_delete_assign_base &&) noexcept = default;
-};
-
-template <class T, class E>
-struct expected_delete_assign_base<T, E, false, false> {
-  expected_delete_assign_base() = default;
-  expected_delete_assign_base(const expected_delete_assign_base &) = default;
-  expected_delete_assign_base(expected_delete_assign_base &&) noexcept =
-      default;
-  expected_delete_assign_base &
-  operator=(const expected_delete_assign_base &) = delete;
-  expected_delete_assign_base &
-  operator=(expected_delete_assign_base &&) noexcept = delete;
-};
-
-// This is needed to be able to construct the expected_default_ctor_base which
-// follows, while still conditionally deleting the default constructor.
-struct default_constructor_tag {
-  explicit constexpr default_constructor_tag() = default;
-};
-
-// expected_default_ctor_base will ensure that expected has a deleted default
-// consturctor if T is not default constructible.
-// This specialization is for when T is default constructible
-template <class T, class E,
-          bool Enable =
-              std::is_default_constructible<T>::value || std::is_void<T>::value>
-struct expected_default_ctor_base {
-  constexpr expected_default_ctor_base() noexcept = default;
-  constexpr expected_default_ctor_base(
-      expected_default_ctor_base const &) noexcept = default;
-  constexpr expected_default_ctor_base(expected_default_ctor_base &&) noexcept =
-      default;
-  expected_default_ctor_base &
-  operator=(expected_default_ctor_base const &) noexcept = default;
-  expected_default_ctor_base &
-  operator=(expected_default_ctor_base &&) noexcept = default;
-
-  constexpr explicit expected_default_ctor_base(default_constructor_tag) {}
-};
-
-// This specialization is for when T is not default constructible
-template <class T, class E> struct expected_default_ctor_base<T, E, false> {
-  constexpr expected_default_ctor_base() noexcept = delete;
-  constexpr expected_default_ctor_base(
-      expected_default_ctor_base const &) noexcept = default;
-  constexpr expected_default_ctor_base(expected_default_ctor_base &&) noexcept =
-      default;
-  expected_default_ctor_base &
-  operator=(expected_default_ctor_base const &) noexcept = default;
-  expected_default_ctor_base &
-  operator=(expected_default_ctor_base &&) noexcept = default;
-
-  constexpr explicit expected_default_ctor_base(default_constructor_tag) {}
-};
-} // namespace detail
-
-template <class E> class bad_expected_access : public std::exception {
-public:
-  explicit bad_expected_access(E e) : m_val(std::move(e)) {}
-
-  virtual const char *what() const noexcept override {
-    return "Bad expected access";
-  }
-
-  const E &error() const & { return m_val; }
-  E &error() & { return m_val; }
-  const E &&error() const && { return std::move(m_val); }
-  E &&error() && { return std::move(m_val); }
-
-private:
-  E m_val;
-};
-
-/// An `expected<T, E>` object is an object that contains the storage for
-/// another object and manages the lifetime of this contained object `T`.
-/// Alternatively it could contain the storage for another unexpected object
-/// `E`. The contained object may not be initialized after the expected object
-/// has been initialized, and may not be destroyed before the expected object
-/// has been destroyed. The initialization state of the contained object is
-/// tracked by the expected object.
-template <class T, class E>
-class expected : private detail::expected_move_assign_base<T, E>,
-                 private detail::expected_delete_ctor_base<T, E>,
-                 private detail::expected_delete_assign_base<T, E>,
-                 private detail::expected_default_ctor_base<T, E> {
-  static_assert(!std::is_reference<T>::value, "T must not be a reference");
-  static_assert(!std::is_same<T, std::remove_cv<in_place_t>>::value,
-                "T must not be in_place_t");
-  static_assert(!std::is_same<T, std::remove_cv<unexpect_t>>::value,
-                "T must not be unexpect_t");
-  static_assert(!std::is_same<T, std::remove_cv<unexpected<E>>>::value,
-                "T must not be unexpected<E>");
-  static_assert(!std::is_reference<E>::value, "E must not be a reference");
-
-  T *valptr() { return std::addressof(this->m_val); }
-  const T *valptr() const { return std::addressof(this->m_val); }    
-  unexpected<E> *errptr() { return std::addressof(this->m_unexpect); }
-  const unexpected<E> *errptr() const { return std::addressof(this->m_unexpect); }    
-
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR U &val() {
-    return this->m_val;
-  }
-  TL_EXPECTED_11_CONSTEXPR unexpected<E> &err() { return this->m_unexpect; }
-
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  constexpr const U &val() const {
-    return this->m_val;
-  }
-  constexpr const unexpected<E> &err() const { return this->m_unexpect; }
-
-  using impl_base = detail::expected_move_assign_base<T, E>;
-  using ctor_base = detail::expected_default_ctor_base<T, E>;
-
-public:
-  typedef T value_type;
-  typedef E error_type;
-  typedef unexpected<E> unexpected_type;
-
-#if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) &&               \
-    !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55)
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto and_then(F &&f) & {
-    return and_then_impl(*this, std::forward<F>(f));
-  }
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto and_then(F &&f) && {
-    return and_then_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F> constexpr auto and_then(F &&f) const & {
-    return and_then_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F> constexpr auto and_then(F &&f) const && {
-    return and_then_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-
-#else
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR auto
-  and_then(F &&f) & -> decltype(and_then_impl(std::declval<expected&>(), std::forward<F>(f))) {
-    return and_then_impl(*this, std::forward<F>(f));
-  }
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR auto and_then(F &&f) && -> decltype(
-      and_then_impl(std::declval<expected&&>(), std::forward<F>(f))) {
-    return and_then_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F>
-  constexpr auto and_then(F &&f) const & -> decltype(
-      and_then_impl(std::declval<expected const&>(), std::forward<F>(f))) {
-    return and_then_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F>
-  constexpr auto and_then(F &&f) const && -> decltype(
-      and_then_impl(std::declval<expected const&&>(), std::forward<F>(f))) {
-    return and_then_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-#endif
-
-#if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) &&               \
-    !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55)
-    template <class F> TL_EXPECTED_11_CONSTEXPR auto map(F &&f) & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto map(F &&f) && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F> constexpr auto map(F &&f) const & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F> constexpr auto map(F &&f) const && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-#else
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(
-      expected_map_impl(std::declval<expected &>(), std::declval<F &&>()))
-  map(F &&f) & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(
-      expected_map_impl(std::declval<expected>(), std::declval<F &&>()))
-  map(F &&f) && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F>
-  constexpr decltype(expected_map_impl(std::declval<const expected &>(),
-                                       std::declval<F &&>()))
-  map(F &&f) const & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F>
-  constexpr decltype(expected_map_impl(std::declval<const expected &&>(),
-                                       std::declval<F &&>()))
-  map(F &&f) const && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-#endif
-
-#if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) &&               \
-    !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55)
-    template <class F> TL_EXPECTED_11_CONSTEXPR auto transform(F &&f) & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto transform(F &&f) && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F> constexpr auto transform(F &&f) const & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F> constexpr auto transform(F &&f) const && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-#else
-    template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(
-      expected_map_impl(std::declval<expected &>(), std::declval<F &&>()))
-  transform(F &&f) & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(
-      expected_map_impl(std::declval<expected>(), std::declval<F &&>()))
-  transform(F &&f) && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F>
-  constexpr decltype(expected_map_impl(std::declval<const expected &>(),
-                                       std::declval<F &&>()))
-  transform(F &&f) const & {
-    return expected_map_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F>
-  constexpr decltype(expected_map_impl(std::declval<const expected &&>(),
-                                       std::declval<F &&>()))
-  transform(F &&f) const && {
-    return expected_map_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-#endif
-
-#if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) &&               \
-    !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55)
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto map_error(F &&f) & {
-    return map_error_impl(*this, std::forward<F>(f));
-  }
-  template <class F> TL_EXPECTED_11_CONSTEXPR auto map_error(F &&f) && {
-    return map_error_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F> constexpr auto map_error(F &&f) const & {
-    return map_error_impl(*this, std::forward<F>(f));
-  }
-  template <class F> constexpr auto map_error(F &&f) const && {
-    return map_error_impl(std::move(*this), std::forward<F>(f));
-  }
-#else
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &>(),
-                                                   std::declval<F &&>()))
-  map_error(F &&f) & {
-    return map_error_impl(*this, std::forward<F>(f));
-  }
-  template <class F>
-  TL_EXPECTED_11_CONSTEXPR decltype(map_error_impl(std::declval<expected &&>(),
-                                                   std::declval<F &&>()))
-  map_error(F &&f) && {
-    return map_error_impl(std::move(*this), std::forward<F>(f));
-  }
-  template <class F>
-  constexpr decltype(map_error_impl(std::declval<const expected &>(),
-                                    std::declval<F &&>()))
-  map_error(F &&f) const & {
-    return map_error_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F>
-  constexpr decltype(map_error_impl(std::declval<const expected &&>(),
-                                    std::declval<F &&>()))
-  map_error(F &&f) const && {
-    return map_error_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-#endif
-  template <class F> expected TL_EXPECTED_11_CONSTEXPR or_else(F &&f) & {
-    return or_else_impl(*this, std::forward<F>(f));
-  }
-
-  template <class F> expected TL_EXPECTED_11_CONSTEXPR or_else(F &&f) && {
-    return or_else_impl(std::move(*this), std::forward<F>(f));
-  }
-
-  template <class F> expected constexpr or_else(F &&f) const & {
-    return or_else_impl(*this, std::forward<F>(f));
-  }
-
-#ifndef TL_EXPECTED_NO_CONSTRR
-  template <class F> expected constexpr or_else(F &&f) const && {
-    return or_else_impl(std::move(*this), std::forward<F>(f));
-  }
-#endif
-  constexpr expected() = default;
-  constexpr expected(const expected &rhs) = default;
-  constexpr expected(expected &&rhs) = default;
-  expected &operator=(const expected &rhs) = default;
-  expected &operator=(expected &&rhs) = default;
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<T, Args &&...>::value> * =
-                nullptr>
-  constexpr expected(in_place_t, Args &&... args)
-      : impl_base(in_place, std::forward<Args>(args)...),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr expected(in_place_t, std::initializer_list<U> il, Args &&... args)
-      : impl_base(in_place, il, std::forward<Args>(args)...),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-  template <class G = E,
-            detail::enable_if_t<std::is_constructible<E, const G &>::value> * =
-                nullptr,
-            detail::enable_if_t<!std::is_convertible<const G &, E>::value> * =
-                nullptr>
-  explicit constexpr expected(const unexpected<G> &e)
-      : impl_base(unexpect, e.value()),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-    template <
-      class G = E,
-      detail::enable_if_t<std::is_constructible<E, const G &>::value> * =
-          nullptr,
-      detail::enable_if_t<std::is_convertible<const G &, E>::value> * = nullptr>
-  constexpr expected(unexpected<G> const &e)
-      : impl_base(unexpect, e.value()),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-  template <
-      class G = E,
-      detail::enable_if_t<std::is_constructible<E, G &&>::value> * = nullptr,
-      detail::enable_if_t<!std::is_convertible<G &&, E>::value> * = nullptr>
-  explicit constexpr expected(unexpected<G> &&e) noexcept(
-      std::is_nothrow_constructible<E, G &&>::value)
-      : impl_base(unexpect, std::move(e.value())),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-    template <
-      class G = E,
-      detail::enable_if_t<std::is_constructible<E, G &&>::value> * = nullptr,
-      detail::enable_if_t<std::is_convertible<G &&, E>::value> * = nullptr>
-  constexpr expected(unexpected<G> &&e) noexcept(
-      std::is_nothrow_constructible<E, G &&>::value)
-      : impl_base(unexpect, std::move(e.value())),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-  template <class... Args,
-            detail::enable_if_t<std::is_constructible<E, Args &&...>::value> * =
-                nullptr>
-  constexpr explicit expected(unexpect_t, Args &&... args)
-      : impl_base(unexpect, std::forward<Args>(args)...),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-    template <class U, class... Args,
-            detail::enable_if_t<std::is_constructible<
-                E, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  constexpr explicit expected(unexpect_t, std::initializer_list<U> il,
-                              Args &&... args)
-      : impl_base(unexpect, il, std::forward<Args>(args)...),
-        ctor_base(detail::default_constructor_tag{}) {}
-
-  template <class U, class G,
-            detail::enable_if_t<!(std::is_convertible<U const &, T>::value &&
-                                  std::is_convertible<G const &, E>::value)> * =
-                nullptr,
-            detail::expected_enable_from_other<T, E, U, G, const U &, const G &>
-                * = nullptr>
-  explicit TL_EXPECTED_11_CONSTEXPR expected(const expected<U, G> &rhs)
-      : ctor_base(detail::default_constructor_tag{}) {
-    if (rhs.has_value()) {
-      this->construct(*rhs);
-    } else {
-      this->construct_error(rhs.error());        
-    }
-  }
-
-    template <class U, class G,
-            detail::enable_if_t<(std::is_convertible<U const &, T>::value &&
-                                 std::is_convertible<G const &, E>::value)> * =
-                nullptr,
-            detail::expected_enable_from_other<T, E, U, G, const U &, const G &>
-                * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR expected(const expected<U, G> &rhs)
-      : ctor_base(detail::default_constructor_tag{}) {
-    if (rhs.has_value()) {
-      this->construct(*rhs);
-    } else {
-      this->construct_error(rhs.error());        
-    }      
-  }
-
-  template <
-      class U, class G,
-      detail::enable_if_t<!(std::is_convertible<U &&, T>::value &&
-                            std::is_convertible<G &&, E>::value)> * = nullptr,
-      detail::expected_enable_from_other<T, E, U, G, U &&, G &&> * = nullptr>
-  explicit TL_EXPECTED_11_CONSTEXPR expected(expected<U, G> &&rhs)
-      : ctor_base(detail::default_constructor_tag{}) {
-    if (rhs.has_value()) {
-      this->construct(std::move(*rhs));
-    } else {
-      this->construct_error(std::move(rhs.error()));        
-    }            
-  }
-
-    template <
-      class U, class G,
-      detail::enable_if_t<(std::is_convertible<U &&, T>::value &&
-                           std::is_convertible<G &&, E>::value)> * = nullptr,
-      detail::expected_enable_from_other<T, E, U, G, U &&, G &&> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR expected(expected<U, G> &&rhs)
-      : ctor_base(detail::default_constructor_tag{}) {
-    if (rhs.has_value()) {
-      this->construct(std::move(*rhs));
-    } else {
-      this->construct_error(std::move(rhs.error()));        
-    }                  
-  }
-
-  template <
-      class U = T,
-      detail::enable_if_t<!std::is_convertible<U &&, T>::value> * = nullptr,
-      detail::expected_enable_forward_value<T, E, U> * = nullptr>
-  explicit TL_EXPECTED_MSVC2015_CONSTEXPR expected(U &&v)
-      : expected(in_place, std::forward<U>(v)) {}
-
-    template <
-      class U = T,
-      detail::enable_if_t<std::is_convertible<U &&, T>::value> * = nullptr,
-      detail::expected_enable_forward_value<T, E, U> * = nullptr>
-  TL_EXPECTED_MSVC2015_CONSTEXPR expected(U &&v)
-      : expected(in_place, std::forward<U>(v)) {}
-
-  template <
-      class U = T, class G = T,
-      detail::enable_if_t<std::is_nothrow_constructible<T, U &&>::value> * =
-          nullptr,
-      detail::enable_if_t<!std::is_void<G>::value> * = nullptr,
-      detail::enable_if_t<
-          (!std::is_same<expected<T, E>, detail::decay_t<U>>::value &&
-           !detail::conjunction<std::is_scalar<T>,
-                                std::is_same<T, detail::decay_t<U>>>::value &&
-           std::is_constructible<T, U>::value &&
-           std::is_assignable<G &, U>::value &&
-           std::is_nothrow_move_constructible<E>::value)> * = nullptr>
-  expected &operator=(U &&v) {
-    if (has_value()) {
-      val() = std::forward<U>(v);
-    } else {
-      err().~unexpected<E>();
-      ::new (valptr()) T(std::forward<U>(v));
-      this->m_has_val = true;
-    }
-
-    return *this;
-  }
-
-    template <
-      class U = T, class G = T,
-      detail::enable_if_t<!std::is_nothrow_constructible<T, U &&>::value> * =
-          nullptr,
-      detail::enable_if_t<!std::is_void<U>::value> * = nullptr,
-      detail::enable_if_t<
-          (!std::is_same<expected<T, E>, detail::decay_t<U>>::value &&
-           !detail::conjunction<std::is_scalar<T>,
-                                std::is_same<T, detail::decay_t<U>>>::value &&
-           std::is_constructible<T, U>::value &&
-           std::is_assignable<G &, U>::value &&
-           std::is_nothrow_move_constructible<E>::value)> * = nullptr>
-  expected &operator=(U &&v) {
-    if (has_value()) {
-      val() = std::forward<U>(v);
-    } else {
-      auto tmp = std::move(err());
-      err().~unexpected<E>();
-
-      #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-      try {
-        ::new (valptr()) T(std::forward<U>(v));
-        this->m_has_val = true;
-      } catch (...) {
-        err() = std::move(tmp);
-        throw;
-      }
-      #else
-        ::new (valptr()) T(std::forward<U>(v));
-        this->m_has_val = true;
-      #endif
-    }
-
-    return *this;
-  }
-
-  template <class G = E,
-            detail::enable_if_t<std::is_nothrow_copy_constructible<G>::value &&
-                                std::is_assignable<G &, G>::value> * = nullptr>
-  expected &operator=(const unexpected<G> &rhs) {
-    if (!has_value()) {
-      err() = rhs;
-    } else {
-      this->destroy_val();
-      ::new (errptr()) unexpected<E>(rhs);
-      this->m_has_val = false;
-    }
-
-    return *this;
-  }
-
-  template <class G = E,
-            detail::enable_if_t<std::is_nothrow_move_constructible<G>::value &&
-                                std::is_move_assignable<G>::value> * = nullptr>
-  expected &operator=(unexpected<G> &&rhs) noexcept {
-    if (!has_value()) {
-      err() = std::move(rhs);
-    } else {
-      this->destroy_val();
-      ::new (errptr()) unexpected<E>(std::move(rhs));
-      this->m_has_val = false;
-    }
-
-    return *this;
-  }
-
-  template <class... Args, detail::enable_if_t<std::is_nothrow_constructible<
-                               T, Args &&...>::value> * = nullptr>
-  void emplace(Args &&... args) {
-    if (has_value()) {
-      val() = T(std::forward<Args>(args)...);
-    } else {
-      err().~unexpected<E>();
-      ::new (valptr()) T(std::forward<Args>(args)...);
-      this->m_has_val = true;
-    }
-  }
-
-    template <class... Args, detail::enable_if_t<!std::is_nothrow_constructible<
-                               T, Args &&...>::value> * = nullptr>
-  void emplace(Args &&... args) {
-    if (has_value()) {
-      val() = T(std::forward<Args>(args)...);
-    } else {
-      auto tmp = std::move(err());
-      err().~unexpected<E>();
-
-      #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-      try {
-        ::new (valptr()) T(std::forward<Args>(args)...);
-        this->m_has_val = true;
-      } catch (...) {
-        err() = std::move(tmp);
-        throw;
-      }
-      #else
-      ::new (valptr()) T(std::forward<Args>(args)...);
-      this->m_has_val = true;
-      #endif
-    }
-  }
-
-  template <class U, class... Args,
-            detail::enable_if_t<std::is_nothrow_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  void emplace(std::initializer_list<U> il, Args &&... args) {
-    if (has_value()) {
-      T t(il, std::forward<Args>(args)...);
-      val() = std::move(t);
-    } else {
-      err().~unexpected<E>();
-      ::new (valptr()) T(il, std::forward<Args>(args)...);
-      this->m_has_val = true;
-    }
-  }
-
-    template <class U, class... Args,
-            detail::enable_if_t<!std::is_nothrow_constructible<
-                T, std::initializer_list<U> &, Args &&...>::value> * = nullptr>
-  void emplace(std::initializer_list<U> il, Args &&... args) {
-    if (has_value()) {
-      T t(il, std::forward<Args>(args)...);
-      val() = std::move(t);
-    } else {
-      auto tmp = std::move(err());
-      err().~unexpected<E>();
-
-      #ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-      try {
-        ::new (valptr()) T(il, std::forward<Args>(args)...);
-        this->m_has_val = true;
-      } catch (...) {
-        err() = std::move(tmp);
-        throw;
-      }
-      #else
-      ::new (valptr()) T(il, std::forward<Args>(args)...);
-      this->m_has_val = true;
-      #endif
-    }
-  }
-
-private:
-  using t_is_void = std::true_type;
-  using t_is_not_void = std::false_type;
-  using t_is_nothrow_move_constructible = std::true_type;
-  using move_constructing_t_can_throw = std::false_type;
-  using e_is_nothrow_move_constructible = std::true_type;
-  using move_constructing_e_can_throw = std::false_type;
-
-  void swap_where_both_have_value(expected &/*rhs*/ , t_is_void) noexcept {
-    // swapping void is a no-op
-  }
-
-  void swap_where_both_have_value(expected &rhs, t_is_not_void) {
-    using std::swap;
-    swap(val(), rhs.val());
-  }
-
-  void swap_where_only_one_has_value(expected &rhs, t_is_void) noexcept(
-      std::is_nothrow_move_constructible<E>::value) {
-    ::new (errptr()) unexpected_type(std::move(rhs.err()));
-    rhs.err().~unexpected_type();
-    std::swap(this->m_has_val, rhs.m_has_val);
-  }
-
-  void swap_where_only_one_has_value(expected &rhs, t_is_not_void) {
-    swap_where_only_one_has_value_and_t_is_not_void(
-        rhs, typename std::is_nothrow_move_constructible<T>::type{},
-        typename std::is_nothrow_move_constructible<E>::type{});
-  }
-
-  void swap_where_only_one_has_value_and_t_is_not_void(
-      expected &rhs, t_is_nothrow_move_constructible,
-      e_is_nothrow_move_constructible) noexcept {
-    auto temp = std::move(val());
-    val().~T();
-    ::new (errptr()) unexpected_type(std::move(rhs.err()));
-    rhs.err().~unexpected_type();
-    ::new (rhs.valptr()) T(std::move(temp));
-    std::swap(this->m_has_val, rhs.m_has_val);
-  }
-
-  void swap_where_only_one_has_value_and_t_is_not_void(
-      expected &rhs, t_is_nothrow_move_constructible,
-      move_constructing_e_can_throw) {
-    auto temp = std::move(val());
-    val().~T();
-#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-    try {
-      ::new (errptr()) unexpected_type(std::move(rhs.err()));
-      rhs.err().~unexpected_type();
-      ::new (rhs.valptr()) T(std::move(temp));
-      std::swap(this->m_has_val, rhs.m_has_val);
-    } catch (...) {
-      val() = std::move(temp);
-      throw;
-    }
-#else
-    ::new (errptr()) unexpected_type(std::move(rhs.err()));
-    rhs.err().~unexpected_type();
-    ::new (rhs.valptr()) T(std::move(temp));
-    std::swap(this->m_has_val, rhs.m_has_val);
-#endif
-  }
-
-  void swap_where_only_one_has_value_and_t_is_not_void(
-      expected &rhs, move_constructing_t_can_throw,
-      t_is_nothrow_move_constructible) {
-    auto temp = std::move(rhs.err());
-    rhs.err().~unexpected_type();
-#ifdef TL_EXPECTED_EXCEPTIONS_ENABLED
-    try {
-      ::new (rhs.valptr()) T(val());
-      val().~T();
-      ::new (errptr()) unexpected_type(std::move(temp));
-      std::swap(this->m_has_val, rhs.m_has_val);
-    } catch (...) {
-      rhs.err() = std::move(temp);
-      throw;
-    }
-#else
-    ::new (rhs.valptr()) T(val());
-    val().~T();
-    ::new (errptr()) unexpected_type(std::move(temp));
-    std::swap(this->m_has_val, rhs.m_has_val);
-#endif
-  }
-
-public:
-  template <class OT = T, class OE = E>
-  detail::enable_if_t<detail::is_swappable<OT>::value &&
-                      detail::is_swappable<OE>::value &&
-                      (std::is_nothrow_move_constructible<OT>::value ||
-                       std::is_nothrow_move_constructible<OE>::value)>
-  swap(expected &rhs) noexcept(
-      std::is_nothrow_move_constructible<T>::value
-          &&detail::is_nothrow_swappable<T>::value
-              &&std::is_nothrow_move_constructible<E>::value
-                  &&detail::is_nothrow_swappable<E>::value) {
-    if (has_value() && rhs.has_value()) {
-      swap_where_both_have_value(rhs, typename std::is_void<T>::type{});
-    } else if (!has_value() && rhs.has_value()) {
-      rhs.swap(*this);
-    } else if (has_value()) {
-      swap_where_only_one_has_value(rhs, typename std::is_void<T>::type{});
-    } else {
-      using std::swap;
-      swap(err(), rhs.err());
-    }
-  }
-
-  constexpr const T *operator->() const { return valptr(); }
-  TL_EXPECTED_11_CONSTEXPR T *operator->() { return valptr(); }
-
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  constexpr const U &operator*() const & {
-    return val();
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR U &operator*() & {
-    return val();
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  constexpr const U &&operator*() const && {
-    return std::move(val());
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR U &&operator*() && {
-    return std::move(val());
-  }
-
-  constexpr bool has_value() const noexcept { return this->m_has_val; }
-  constexpr explicit operator bool() const noexcept { return this->m_has_val; }
-
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR const U &value() const & {
-    if (!has_value())
-      detail::throw_exception(bad_expected_access<E>(err().value()));
-    return val();
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR U &value() & {
-    if (!has_value())
-      detail::throw_exception(bad_expected_access<E>(err().value()));
-    return val();
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR const U &&value() const && {
-    if (!has_value())
-      detail::throw_exception(bad_expected_access<E>(std::move(err()).value()));
-    return std::move(val());
-  }
-  template <class U = T,
-            detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
-  TL_EXPECTED_11_CONSTEXPR U &&value() && {
-    if (!has_value())
-      detail::throw_exception(bad_expected_access<E>(std::move(err()).value()));
-    return std::move(val());
-  }
-
-  constexpr const E &error() const & { return err().value(); }
-  TL_EXPECTED_11_CONSTEXPR E &error() & { return err().value(); }
-  constexpr const E &&error() const && { return std::move(err().value()); }
-  TL_EXPECTED_11_CONSTEXPR E &&error() && { return std::move(err().value()); }
-
-  template <class U> constexpr T value_or(U &&v) const & {
-    static_assert(std::is_copy_constructible<T>::value &&
-                      std::is_convertible<U &&, T>::value,
-                  "T must be copy-constructible and convertible to from U&&");
-    return bool(*this) ? **this : static_cast<T>(std::forward<U>(v));
-  }
-  template <class U> TL_EXPECTED_11_CONSTEXPR T value_or(U &&v) && {
-    static_assert(std::is_move_constructible<T>::value &&
-                      std::is_convertible<U &&, T>::value,
-                  "T must be move-constructible and convertible to from U&&");
-    return bool(*this) ? std::move(**this) : static_cast<T>(std::forward<U>(v));
-  }
-};
-
-namespace detail {
-template <class Exp> using exp_t = typename detail::decay_t<Exp>::value_type;
-template <class Exp> using err_t = typename detail::decay_t<Exp>::error_type;
-template <class Exp, class Ret> using ret_t = expected<Ret, err_t<Exp>>;
-
-#ifdef TL_EXPECTED_CXX14
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>()))>
-constexpr auto and_then_impl(Exp &&exp, F &&f) {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-
-  return exp.has_value()
-             ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp))
-             : Ret(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,
-          class Ret = decltype(detail::invoke(std::declval<F>()))>
-constexpr auto and_then_impl(Exp &&exp, F &&f) {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-
-  return exp.has_value() ? detail::invoke(std::forward<F>(f))
-                         : Ret(unexpect, std::forward<Exp>(exp).error());
-}
-#else
-template <class> struct TC;
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>())),
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr>
-auto and_then_impl(Exp &&exp, F &&f) -> Ret {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-
-  return exp.has_value()
-             ? detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp))
-             : Ret(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>())),
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr>
-constexpr auto and_then_impl(Exp &&exp, F &&f) -> Ret {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-
-  return exp.has_value() ? detail::invoke(std::forward<F>(f))
-                         : Ret(unexpect, std::forward<Exp>(exp).error());
-}
-#endif
-
-#ifdef TL_EXPECTED_CXX14
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto expected_map_impl(Exp &&exp, F &&f) {
-  using result = ret_t<Exp, detail::decay_t<Ret>>;
-  return exp.has_value() ? result(detail::invoke(std::forward<F>(f),
-                                                 *std::forward<Exp>(exp)))
-                         : result(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto expected_map_impl(Exp &&exp, F &&f) {
-  using result = expected<void, err_t<Exp>>;
-  if (exp.has_value()) {
-    detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp));
-    return result();
-  }
-
-  return result(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,
-          class Ret = decltype(detail::invoke(std::declval<F>())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto expected_map_impl(Exp &&exp, F &&f) {
-  using result = ret_t<Exp, detail::decay_t<Ret>>;
-  return exp.has_value() ? result(detail::invoke(std::forward<F>(f)))
-                         : result(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto expected_map_impl(Exp &&exp, F &&f) {
-  using result = expected<void, err_t<Exp>>;
-  if (exp.has_value()) {
-    detail::invoke(std::forward<F>(f));
-    return result();
-  }
-
-  return result(unexpect, std::forward<Exp>(exp).error());
-}    
-#else
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-
-constexpr auto expected_map_impl(Exp &&exp, F &&f)
-    -> ret_t<Exp, detail::decay_t<Ret>> {
-  using result = ret_t<Exp, detail::decay_t<Ret>>;
-
-  return exp.has_value() ? result(detail::invoke(std::forward<F>(f),
-                                                 *std::forward<Exp>(exp)))
-                         : result(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,                    
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              *std::declval<Exp>())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-
-auto expected_map_impl(Exp &&exp, F &&f) -> expected<void, err_t<Exp>> {
-  if (exp.has_value()) {
-    detail::invoke(std::forward<F>(f), *std::forward<Exp>(exp));
-    return {};
-  }
-
-  return unexpected<err_t<Exp>>(std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,                              
-          class Ret = decltype(detail::invoke(std::declval<F>())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-
-constexpr auto expected_map_impl(Exp &&exp, F &&f)
-    -> ret_t<Exp, detail::decay_t<Ret>> {
-  using result = ret_t<Exp, detail::decay_t<Ret>>;
-
-  return exp.has_value() ? result(detail::invoke(std::forward<F>(f)))
-                         : result(unexpect, std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,                                        
-          class Ret = decltype(detail::invoke(std::declval<F>())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-
-auto expected_map_impl(Exp &&exp, F &&f) -> expected<void, err_t<Exp>> {
-  if (exp.has_value()) {
-    detail::invoke(std::forward<F>(f));
-    return {};
-  }
-
-  return unexpected<err_t<Exp>>(std::forward<Exp>(exp).error());
-}    
-#endif
-
-#if defined(TL_EXPECTED_CXX14) && !defined(TL_EXPECTED_GCC49) &&               \
-    !defined(TL_EXPECTED_GCC54) && !defined(TL_EXPECTED_GCC55)
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto map_error_impl(Exp &&exp, F &&f) {
-  using result = expected<exp_t<Exp>, detail::decay_t<Ret>>;
-  return exp.has_value()
-             ? result(*std::forward<Exp>(exp))
-             : result(unexpect, detail::invoke(std::forward<F>(f),
-                                               std::forward<Exp>(exp).error()));
-}
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,                    
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto map_error_impl(Exp &&exp, F &&f) {
-  using result = expected<exp_t<Exp>, monostate>;
-  if (exp.has_value()) {
-    return result(*std::forward<Exp>(exp));
-  }
-
-  detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-  return result(unexpect, monostate{});
-}
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,          
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto map_error_impl(Exp &&exp, F &&f) {
-  using result = expected<exp_t<Exp>, detail::decay_t<Ret>>;
-  return exp.has_value()
-             ? result()
-             : result(unexpect, detail::invoke(std::forward<F>(f),
-                                               std::forward<Exp>(exp).error()));
-}
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,                    
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto map_error_impl(Exp &&exp, F &&f) {
-  using result = expected<exp_t<Exp>, monostate>;
-  if (exp.has_value()) {
-    return result();
-  }
-
-  detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-  return result(unexpect, monostate{});
-}    
-#else
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,                              
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto map_error_impl(Exp &&exp, F &&f)
-    -> expected<exp_t<Exp>, detail::decay_t<Ret>> {
-  using result = expected<exp_t<Exp>, detail::decay_t<Ret>>;
-
-  return exp.has_value()
-             ? result(*std::forward<Exp>(exp))
-             : result(unexpect, detail::invoke(std::forward<F>(f),
-                                               std::forward<Exp>(exp).error()));
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<!std::is_void<exp_t<Exp>>::value> * = nullptr,                                        
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto map_error_impl(Exp &&exp, F &&f) -> expected<exp_t<Exp>, monostate> {
-  using result = expected<exp_t<Exp>, monostate>;
-  if (exp.has_value()) {
-    return result(*std::forward<Exp>(exp));
-  }
-
-  detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-  return result(unexpect, monostate{});
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,                              
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto map_error_impl(Exp &&exp, F &&f)
-    -> expected<exp_t<Exp>, detail::decay_t<Ret>> {
-  using result = expected<exp_t<Exp>, detail::decay_t<Ret>>;
-
-  return exp.has_value()
-             ? result()
-             : result(unexpect, detail::invoke(std::forward<F>(f),
-                                               std::forward<Exp>(exp).error()));
-}
-
-template <class Exp, class F,
-          detail::enable_if_t<std::is_void<exp_t<Exp>>::value> * = nullptr,                                        
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-auto map_error_impl(Exp &&exp, F &&f) -> expected<exp_t<Exp>, monostate> {
-  using result = expected<exp_t<Exp>, monostate>;
-  if (exp.has_value()) {
-    return result();
-  }
-
-  detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-  return result(unexpect, monostate{});
-}    
-#endif
-
-#ifdef TL_EXPECTED_CXX14
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-constexpr auto or_else_impl(Exp &&exp, F &&f) {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-  return exp.has_value()
-  ? std::forward<Exp>(exp)
-  : detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-          detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) {
-  return exp.has_value()
-  ? std::forward<Exp>(exp)
-  : (detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()),
-    std::forward<Exp>(exp));
-}
-#else
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-  detail::enable_if_t<!std::is_void<Ret>::value> * = nullptr>
-auto or_else_impl(Exp &&exp, F &&f) -> Ret {
-  static_assert(detail::is_expected<Ret>::value, "F must return an expected");
-  return exp.has_value()
-         ? std::forward<Exp>(exp)
-         : detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error());
-}
-
-template <class Exp, class F,
-          class Ret = decltype(detail::invoke(std::declval<F>(),
-                                              std::declval<Exp>().error())),
-  detail::enable_if_t<std::is_void<Ret>::value> * = nullptr>
-detail::decay_t<Exp> or_else_impl(Exp &&exp, F &&f) {
-  return exp.has_value()
-         ? std::forward<Exp>(exp)
-         : (detail::invoke(std::forward<F>(f), std::forward<Exp>(exp).error()),
-            std::forward<Exp>(exp));
-}
-#endif
-} // namespace detail
-
-template <class T, class E, class U, class F>
-constexpr bool operator==(const expected<T, E> &lhs,
-                          const expected<U, F> &rhs) {
-  return (lhs.has_value() != rhs.has_value())
-             ? false
-             : (!lhs.has_value() ? lhs.error() == rhs.error() : *lhs == *rhs);
-}
-template <class T, class E, class U, class F>
-constexpr bool operator!=(const expected<T, E> &lhs,
-                          const expected<U, F> &rhs) {
-  return (lhs.has_value() != rhs.has_value())
-             ? true
-             : (!lhs.has_value() ? lhs.error() != rhs.error() : *lhs != *rhs);
-}
-
-template <class T, class E, class U>
-constexpr bool operator==(const expected<T, E> &x, const U &v) {
-  return x.has_value() ? *x == v : false;
-}
-template <class T, class E, class U>
-constexpr bool operator==(const U &v, const expected<T, E> &x) {
-  return x.has_value() ? *x == v : false;
-}
-template <class T, class E, class U>
-constexpr bool operator!=(const expected<T, E> &x, const U &v) {
-  return x.has_value() ? *x != v : true;
-}
-template <class T, class E, class U>
-constexpr bool operator!=(const U &v, const expected<T, E> &x) {
-  return x.has_value() ? *x != v : true;
-}
-
-template <class T, class E>
-constexpr bool operator==(const expected<T, E> &x, const unexpected<E> &e) {
-  return x.has_value() ? false : x.error() == e.value();
-}
-template <class T, class E>
-constexpr bool operator==(const unexpected<E> &e, const expected<T, E> &x) {
-  return x.has_value() ? false : x.error() == e.value();
-}
-template <class T, class E>
-constexpr bool operator!=(const expected<T, E> &x, const unexpected<E> &e) {
-  return x.has_value() ? true : x.error() != e.value();
-}
-template <class T, class E>
-constexpr bool operator!=(const unexpected<E> &e, const expected<T, E> &x) {
-  return x.has_value() ? true : x.error() != e.value();
-}
-
-template <class T, class E,
-          detail::enable_if_t<(std::is_void<T>::value ||
-                               std::is_move_constructible<T>::value) &&
-                              detail::is_swappable<T>::value &&
-                              std::is_move_constructible<E>::value &&
-                              detail::is_swappable<E>::value> * = nullptr>
-void swap(expected<T, E> &lhs,
-          expected<T, E> &rhs) noexcept(noexcept(lhs.swap(rhs))) {
-  lhs.swap(rhs);
-}
-} // namespace tl
-
-#endif