more

include/continuable/detail/awaiting.hpp

@@ -44,6 +44,10 @@
 #include <continuable/detail/types.hpp>
 #include <continuable/detail/util.hpp>
 
+#if defined(CONTINUABLE_WITH_EXCEPTIONS)
+#include <exception>
+#endif // CONTINUABLE_WITH_EXCEPTIONS
+
 namespace cti {
 namespace detail {
 namespace awaiting {
@@ -131,12 +135,18 @@ public:
         .done();
   }
 
-  void await_resume() {
+  auto await_resume() noexcept(false) {
     if (result_) {
-      return result_.get_value();
-    } else {
-      throw result_.get_error();
+      // When the result was resolved return it
+      trait_t::unwrap(std::move(result_));
     }
+
+#if defined(CONTINUABLE_WITH_EXCEPTIONS)
+    std::rethrow_exception(result_.get_error());
+#else  // CONTINUABLE_WITH_EXCEPTIONS
+    // Returning error types in await isn't supported as of now
+    util::trap();
+#endif // CONTINUABLE_WITH_EXCEPTIONS
   }
 
 private:

include/continuable/detail/base.hpp

@@ -35,17 +35,17 @@
 #include <type_traits>
 #include <utility>
 
-#if !defined(CONTINUABLE_WITH_CUSTOM_ERROR_TYPE) &&                            \
-    !defined(CONTINUABLE_WITH_NO_EXCEPTIONS)
-#include <exception>
-#endif
-
 #include <continuable/continuable-api.hpp>
+#include <continuable/detail/features.hpp>
 #include <continuable/detail/hints.hpp>
 #include <continuable/detail/traits.hpp>
 #include <continuable/detail/types.hpp>
 #include <continuable/detail/util.hpp>
 
+#if defined(CONTINUABLE_WITH_EXCEPTIONS)
+#include <exception>
+#endif // CONTINUABLE_WITH_EXCEPTIONS
+
 namespace cti {
 namespace detail {
 /// The namespace `base` provides the low level API for working
@@ -151,8 +151,7 @@ public:
   }
 };
 
-#if !defined(CONTINUABLE_WITH_CUSTOM_ERROR_TYPE) &&                            \
-    !defined(CONTINUABLE_WITH_NO_EXCEPTIONS)
+#if defined(CONTINUABLE_WITH_EXCEPTIONS)
 #define CONTINUABLE_BLOCK_TRY_BEGIN try {
 #define CONTINUABLE_BLOCK_TRY_END                                              \
   }                                                                            \
@@ -161,10 +160,10 @@ public:
         types::dispatch_error_tag{}, std::current_exception());                \
   }
 
-#else
+#else // CONTINUABLE_WITH_EXCEPTIONS
 #define CONTINUABLE_BLOCK_TRY_BEGIN {
 #define CONTINUABLE_BLOCK_TRY_END }
-#endif
+#endif // CONTINUABLE_WITH_EXCEPTIONS
 
 template <typename T, typename... Args>
 constexpr auto make_invoker(T&& invoke, hints::signature_hint_tag<Args...>) {

include/continuable/detail/expected.hpp

@@ -52,8 +52,46 @@ using storage_of_t = //
                                 ? sizeof(types::error_type)
                                 : sizeof(T))>;
 
+template <typename Base>
+struct expected_move_base {
+  constexpr expected_move_base() = default;
+
+  expected_move_base(expected_move_base const&) = default;
+  explicit expected_move_base(expected_move_base&& right) {
+    Base& me = *static_cast<Base*>(this);
+    Base& other = *static_cast<Base*>(&right);
+    assert(!other.is_empty());
+
+#ifndef _NDEBUG
+    me.set(slot_t::empty);
+#endif
+
+    other.visit([&](auto&& value) {
+      // ...
+      me.init(std::move(value));
+    });
+    me.set(other.get());
+    other.destroy();
+  }
+  expected_move_base& operator=(expected_move_base const&) = default;
+  expected_move_base& operator=(expected_move_base&& right) {
+    Base& me = *static_cast<Base*>(this);
+    Base& other = *static_cast<Base*>(&right);
+    assert(!other.is_empty());
+
+    me.weak_destroy();
+
+    other.visit([&](auto&& value) {
+      // ...
+      me.init(std::move(value));
+    });
+    me.set(other.get());
+    other.destroy();
+    return *this;
+  }
+};
 template <typename Base, bool IsCopyable /*= true*/>
-struct expected_copy_base {
+struct expected_copy_base : expected_move_base<Base> {
   constexpr expected_copy_base() = default;
 
   expected_copy_base(expected_copy_base&&) = default;
@@ -62,6 +100,7 @@ struct expected_copy_base {
   {
     Base& me = *static_cast<Base*>(this);
     Base const& other = *static_cast<Base const*>(&right);
+    assert(!other->is_empty());
 
 #ifndef _NDEBUG
     me.set(slot_t::empty);
@@ -79,6 +118,7 @@ struct expected_copy_base {
   {
     Base& me = *static_cast<Base*>(this);
     Base const& other = *static_cast<Base const*>(&right);
+    assert(!other.is_empty());
 
     me.weak_destroy();
 
@@ -91,7 +131,7 @@ struct expected_copy_base {
   }
 };
 template <typename Base /*, bool IsCopyable = false*/>
-struct expected_copy_base<Base, false> {
+struct expected_copy_base<Base, false> : expected_move_base<Base> {
   constexpr expected_copy_base() = default;
 
   expected_copy_base(expected_copy_base const&) = default;
@@ -99,40 +139,6 @@ struct expected_copy_base<Base, false> {
   expected_copy_base& operator=(expected_copy_base const&) = default;
   expected_copy_base& operator=(expected_copy_base&& right) = delete;
 };
-template <typename Base>
-struct expected_move_base {
-  constexpr expected_move_base() = default;
-
-  expected_move_base(expected_move_base const&) = default;
-  explicit expected_move_base(expected_move_base&& right) {
-    Base& me = *static_cast<Base*>(this);
-    Base& other = *static_cast<Base*>(&right);
-
-#ifndef _NDEBUG
-    me.set(slot_t::empty);
-#endif
-
-    other.visit([&](auto&& value) {
-      // ...
-      me.init(std::move(value));
-    });
-    me.set(other.consume());
-  }
-  expected_move_base& operator=(expected_move_base const&) = default;
-  expected_move_base& operator=(expected_move_base&& right) {
-    Base& me = *static_cast<Base*>(this);
-    Base& other = *static_cast<Base*>(&right);
-
-    me.weak_destroy();
-
-    other.visit([&](auto&& value) {
-      // ...
-      me.init(std::move(value));
-    });
-    me.set(other.consume());
-    return *this;
-  }
-};
 } // namespace detail
 
 /// A class similar to the one in the expected proposal,
@@ -140,8 +146,7 @@ struct expected_move_base {
 /// exceptions are used.
 template <typename T>
 class expected
-    : detail::expected_move_base<expected<T>>,
-      detail::expected_copy_base<
+    : detail::expected_copy_base<
           expected<T>, std::is_copy_constructible<types::error_type>::value &&
                            std::is_copy_constructible<T>::value> {
 
@@ -153,7 +158,7 @@ class expected
   friend struct detail::expected_copy_base;
 
   detail::storage_of_t<T> storage_;
-  detail::slot_t slot_ = detail::slot_t::empty;
+  detail::slot_t slot_;
 
   template <typename V>
   expected(V&& value, detail::slot_t const slot) {
@@ -163,7 +168,13 @@ class expected
   }
 
 public:
-  expected() = default;
+  constexpr expected() : slot_(detail::slot_t::empty) {
+  }
+
+  expected(expected const&) = default;
+  expected(expected&&) = default;
+  expected& operator=(expected const&) = default;
+  expected& operator=(expected&&) = default;
 
   explicit expected(T value) //
       : expected(std::move(value), detail::slot_t::value) {
@@ -181,18 +192,13 @@ public:
     return *this;
   }
 
-  expected(expected const&) = default;
-  expected(expected&& right) = default;
-  expected& operator=(expected const&) = default;
-  expected& operator=(expected&& right) = default;
-
   bool is_value() const noexcept {
     assert(!is_empty());
-    return slot_ == detail::slot_t::value;
+    return is(detail::slot_t::value);
   }
   bool is_exception() const noexcept {
     assert(!is_empty());
-    return slot_ == detail::slot_t::error;
+    return is(detail::slot_t::error);
   }
 
   explicit constexpr operator bool() const noexcept {
@@ -261,7 +267,7 @@ private:
   }
 
   bool is_empty() const noexcept {
-    return slot_ == detail::slot_t::empty;
+    return is(detail::slot_t::empty);
   }
 
   template <typename V>
@@ -308,11 +314,6 @@ private:
   void set(detail::slot_t const slot) {
     slot_ = slot;
   }
-  detail::slot_t consume() {
-    auto const current = get();
-    destroy();
-    return current;
-  }
 };
 } // namespace util
 } // namespace detail

include/continuable/detail/features.hpp

@@ -47,6 +47,14 @@
 #endif
 #endif // CONTINUABLE_WITH_NO_EXCEPTIONS
 
+/// Define CONTINUABLE_WITH_EXCEPTIONS when exceptions are used
+#if !defined(CONTINUABLE_WITH_CUSTOM_ERROR_TYPE) &&                            \
+    !defined(CONTINUABLE_WITH_NO_EXCEPTIONS)
+#define CONTINUABLE_WITH_EXCEPTIONS 1
+#else
+#undef CONTINUABLE_WITH_EXCEPTIONS
+#endif
+
 /// TODO Enable this
 #undef CONTINUABLE_HAS_CXX17_CONSTEXPR_IF
 /// TODO Enable this

test/unit-test/test-continuable-expected.cpp

@@ -106,8 +106,7 @@ TYPED_TEST(expected_all_tests, is_move_constructible) {
   }
 }
 
-TYPED_TEST(expected_all_tests, is_move_assignable) {
-  {
+TYPED_TEST(expected_all_tests, is_value_move_assignable) {
   TypeParam old(this->supply(CANARY));
   TypeParam e;
   e = std::move(old);
@@ -116,9 +115,9 @@ TYPED_TEST(expected_all_tests, is_move_assignable) {
   EXPECT_EQ(this->get(*e), CANARY);
   EXPECT_TRUE(e.is_value());
   EXPECT_FALSE(e.is_exception());
-  }
+}
 
-  {
+TYPED_TEST(expected_all_tests, is_error_move_assignable) {
   TypeParam old(error_type{});
   TypeParam e;
   e = std::move(old);
@@ -126,7 +125,6 @@ TYPED_TEST(expected_all_tests, is_move_assignable) {
   EXPECT_FALSE(bool(e));
   EXPECT_FALSE(e.is_value());
   EXPECT_TRUE(e.is_exception());
-  }
 }
 
 TYPED_TEST(expected_all_tests, is_value_assignable) {