From 74155db2438108b347f009c686fadcb7db82f8db Mon Sep 17 00:00:00 2001
From: Simon Brand <simon@codeplay.com>
Date: Fri, 11 May 2018 10:20:37 +0100
Subject: [PATCH] Fix #15

---
 tl/expected.hpp | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/tl/expected.hpp b/tl/expected.hpp
index ee329c3..09370a5 100644
--- a/tl/expected.hpp
+++ b/tl/expected.hpp
@@ -184,6 +184,19 @@ static constexpr unexpect_t unexpect{};
 
 /// \exclude
 namespace detail {
+template<typename E>
+[[noreturn]] constexpr void throw_exception(E &&e) {
+#if defined(__EXCEPTIONS) || defined(_CPPUNWIND)
+    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
@@ -1729,7 +1742,7 @@ public:
             detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
   TL_EXPECTED_11_CONSTEXPR const U &value() const & {
     if (!has_value())
-      throw bad_expected_access<E>(err().value());
+      detail::throw_exception(bad_expected_access<E>(err().value()));
     return val();
   }
   /// \group value
@@ -1737,7 +1750,7 @@ public:
             detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
   TL_EXPECTED_11_CONSTEXPR U &value() & {
     if (!has_value())
-      throw bad_expected_access<E>(err().value());
+      detail::throw_exception(bad_expected_access<E>(err().value()));
     return val();
   }
   /// \group value
@@ -1745,7 +1758,7 @@ public:
             detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
   TL_EXPECTED_11_CONSTEXPR const U &&value() const && {
     if (!has_value())
-      throw bad_expected_access<E>(err().value());
+      detail::throw_exception(bad_expected_access<E>(err().value()));
     return std::move(val());
   }
   /// \group value
@@ -1753,7 +1766,7 @@ public:
             detail::enable_if_t<!std::is_void<U>::value> * = nullptr>
   TL_EXPECTED_11_CONSTEXPR U &&value() && {
     if (!has_value())
-      throw bad_expected_access<E>(err().value());
+      detail::throw_exception(bad_expected_access<E>(err().value()));
     return std::move(val());
   }