diff --git a/libcxx/include/__functional/operations.h b/libcxx/include/__functional/operations.h
--- a/libcxx/include/__functional/operations.h
+++ b/libcxx/include/__functional/operations.h
@@ -53,9 +53,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -90,9 +90,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -127,9 +127,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -164,9 +164,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -201,9 +201,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -237,9 +237,9 @@
     template <class _Tp>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(- _VSTD::forward<_Tp>(__x)))
-    -> decltype        (- _VSTD::forward<_Tp>(__x))
-        { return        - _VSTD::forward<_Tp>(__x); }
+        noexcept(noexcept(- _VSTD::forward<_Tp>(__x)))
+        -> decltype(      - _VSTD::forward<_Tp>(__x))
+        { return          - _VSTD::forward<_Tp>(__x); }
     typedef void is_transparent;
 };
 #endif
@@ -276,9 +276,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -307,9 +307,9 @@
     template <class _Tp>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(~_VSTD::forward<_Tp>(__x)))
-    -> decltype        (~_VSTD::forward<_Tp>(__x))
-        { return        ~_VSTD::forward<_Tp>(__x); }
+        noexcept(noexcept(~_VSTD::forward<_Tp>(__x)))
+        -> decltype(      ~_VSTD::forward<_Tp>(__x))
+        { return          ~_VSTD::forward<_Tp>(__x); }
     typedef void is_transparent;
 };
 #endif
@@ -344,9 +344,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -381,9 +381,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -420,9 +420,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -457,9 +457,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -494,9 +494,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -531,9 +531,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -568,9 +568,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -605,9 +605,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -644,9 +644,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
@@ -680,9 +680,9 @@
     template <class _Tp>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(!_VSTD::forward<_Tp>(__x)))
-    -> decltype        (!_VSTD::forward<_Tp>(__x))
-        { return        !_VSTD::forward<_Tp>(__x); }
+        noexcept(noexcept(!_VSTD::forward<_Tp>(__x)))
+        -> decltype(      !_VSTD::forward<_Tp>(__x))
+        { return          !_VSTD::forward<_Tp>(__x); }
     typedef void is_transparent;
 };
 #endif
@@ -717,9 +717,9 @@
     template <class _T1, class _T2>
     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
     auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
+        noexcept(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
+        -> decltype(      _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
+        { return          _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
     typedef void is_transparent;
 };
 #endif
diff --git a/libcxx/include/__ranges/iota_view.h b/libcxx/include/__ranges/iota_view.h
--- a/libcxx/include/__ranges/iota_view.h
+++ b/libcxx/include/__ranges/iota_view.h
@@ -374,19 +374,15 @@
     _LIBCPP_HIDE_FROM_ABI
     constexpr auto operator()(_Start&& __start) const
       noexcept(noexcept(ranges::iota_view(_VSTD::forward<_Start>(__start))))
-            -> decltype(ranges::iota_view(_VSTD::forward<_Start>(__start)))
-    {
-                 return ranges::iota_view(_VSTD::forward<_Start>(__start));
-    }
+      -> decltype(      ranges::iota_view(_VSTD::forward<_Start>(__start)))
+      { return          ranges::iota_view(_VSTD::forward<_Start>(__start)); }
 
     template<class _Start, class _Bound>
     _LIBCPP_HIDE_FROM_ABI
     constexpr auto operator()(_Start&& __start, _Bound&& __bound) const
       noexcept(noexcept(ranges::iota_view(_VSTD::forward<_Start>(__start), _VSTD::forward<_Bound>(__bound))))
-            -> decltype(ranges::iota_view(_VSTD::forward<_Start>(__start), _VSTD::forward<_Bound>(__bound)))
-    {
-                 return ranges::iota_view(_VSTD::forward<_Start>(__start), _VSTD::forward<_Bound>(__bound));
-    }
+      -> decltype(      ranges::iota_view(_VSTD::forward<_Start>(__start), _VSTD::forward<_Bound>(__bound)))
+      { return          ranges::iota_view(_VSTD::forward<_Start>(__start), _VSTD::forward<_Bound>(__bound)); }
   };
 } // namespace __iota
 
diff --git a/libcxx/include/type_traits b/libcxx/include/type_traits
--- a/libcxx/include/type_traits
+++ b/libcxx/include/type_traits
@@ -3811,10 +3811,6 @@
 
 // fall back - none of the bullets
 
-#define _LIBCPP_INVOKE_RETURN(...) \
-    noexcept(noexcept(__VA_ARGS__)) -> decltype(__VA_ARGS__) \
-    { return __VA_ARGS__; }
-
 template <class ..._Args>
 auto __invoke(__any, _Args&& ...__args) -> __nat;
 
@@ -3828,42 +3824,54 @@
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...))
+    { return          (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class _A0, class ..._Args,
           class = __enable_if_bullet1<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept((static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...))
+    { return          (static_cast<_A0&&>(__a0).*__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class _A0, class ..._Args,
           class = __enable_if_bullet2<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((__a0.get().*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept((__a0.get().*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      (__a0.get().*__f)(static_cast<_Args&&>(__args)...))
+    { return          (__a0.get().*__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class _A0, class ..._Args,
           class = __enable_if_bullet2<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((__a0.get().*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept((__a0.get().*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      (__a0.get().*__f)(static_cast<_Args&&>(__args)...))
+    { return          (__a0.get().*__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class _A0, class ..._Args,
           class = __enable_if_bullet3<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...))
+    { return          ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class _A0, class ..._Args,
           class = __enable_if_bullet3<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept(((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...))
+    { return          ((*static_cast<_A0&&>(__a0)).*__f)(static_cast<_Args&&>(__args)...); }
 
 // bullets 4, 5 and 6
 
@@ -3872,42 +3880,54 @@
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(static_cast<_A0&&>(__a0).*__f)
+    noexcept(noexcept(static_cast<_A0&&>(__a0).*__f))
+    -> decltype(      static_cast<_A0&&>(__a0).*__f)
+    { return          static_cast<_A0&&>(__a0).*__f; }
 
 template <class _Fp, class _A0,
           class = __enable_if_bullet4<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(static_cast<_A0&&>(__a0).*__f)
+    noexcept(noexcept(static_cast<_A0&&>(__a0).*__f))
+    -> decltype(      static_cast<_A0&&>(__a0).*__f)
+    { return          static_cast<_A0&&>(__a0).*__f; }
 
 template <class _Fp, class _A0,
           class = __enable_if_bullet5<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(__a0.get().*__f)
+    noexcept(noexcept(__a0.get().*__f))
+    -> decltype(      __a0.get().*__f)
+    { return          __a0.get().*__f; }
 
 template <class _Fp, class _A0,
           class = __enable_if_bullet5<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(__a0.get().*__f)
+    noexcept(noexcept(__a0.get().*__f))
+    -> decltype(      __a0.get().*__f)
+    { return          __a0.get().*__f; }
 
 template <class _Fp, class _A0,
           class = __enable_if_bullet6<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN((*static_cast<_A0&&>(__a0)).*__f)
+    noexcept(noexcept((*static_cast<_A0&&>(__a0)).*__f))
+    -> decltype(      (*static_cast<_A0&&>(__a0)).*__f)
+    { return          (*static_cast<_A0&&>(__a0)).*__f; }
 
 template <class _Fp, class _A0,
           class = __enable_if_bullet6<_Fp, _A0>>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN((*static_cast<_A0&&>(__a0)).*__f)
+    noexcept(noexcept((*static_cast<_A0&&>(__a0)).*__f))
+    -> decltype(      (*static_cast<_A0&&>(__a0)).*__f)
+    { return          (*static_cast<_A0&&>(__a0)).*__f; }
 
 // bullet 7
 
@@ -3915,15 +3935,17 @@
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR_AFTER_CXX17 auto
 __invoke(_Fp&& __f, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...))
+    noexcept(noexcept(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...))
+    { return          static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...); }
 
 template <class _Fp, class ..._Args>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR auto
 __invoke_constexpr(_Fp&& __f, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...))
-
-#undef _LIBCPP_INVOKE_RETURN
+    noexcept(noexcept(static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...)))
+    -> decltype(      static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...))
+    { return          static_cast<_Fp&&>(__f)(static_cast<_Args&&>(__args)...); }
 
 // __invokable
 template <class _Ret, class _Fp, class ..._Args>
diff --git a/libcxx/include/variant b/libcxx/include/variant
--- a/libcxx/include/variant
+++ b/libcxx/include/variant
@@ -1718,11 +1718,10 @@
 
 template <class... _Types>
 inline _LIBCPP_INLINE_VISIBILITY
-auto swap(variant<_Types...>& __lhs,
-          variant<_Types...>& __rhs) noexcept(noexcept(__lhs.swap(__rhs)))
-    -> decltype(__lhs.swap(__rhs)) {
-  __lhs.swap(__rhs);
-}
+auto swap(variant<_Types...>& __lhs, variant<_Types...>& __rhs)
+  noexcept(noexcept(__lhs.swap(__rhs)))
+  -> decltype(      __lhs.swap(__rhs))
+  { return          __lhs.swap(__rhs); }
 
 template <class... _Types>
 struct _LIBCPP_TEMPLATE_VIS hash<