Update single header

tcbrindle · Dec 13, 2023 · a45d844 · a45d844
1 parent 9adb7f4
commit a45d844
Showing 1 changed file with 23 additions and 8 deletions.
diff --git a/single_include/flux.hpp b/single_include/flux.hpp
@@ -1090,11 +1090,16 @@ class optional<T> {
     constexpr optional& operator=(optional const& other)
         noexcept(std::is_nothrow_copy_assignable_v<T> &&
                  std::is_nothrow_copy_constructible_v<T>)
-        requires std::copyable<T>
+        requires std::copy_constructible<T>
     {
         if (engaged_) {
             if (other.engaged_) {
-                item_ = other.item_;
+                if constexpr (std::is_copy_assignable_v<T>) {
+                    item_ = other.item_;
+                } else {
+                    reset();
+                    construct(other.item_);
+                }
             } else {
                 reset();
             }
@@ -1107,7 +1112,8 @@ class optional<T> {
     }
 
     optional& operator=(optional const&)
-        requires std::copyable<T> && std::is_trivially_copy_assignable_v<T>
+        requires std::copy_constructible<T> &&
+                 std::is_trivially_copy_assignable_v<T>
         = default;
 
     /*
@@ -1133,11 +1139,16 @@ class optional<T> {
     constexpr optional& operator=(optional&& other)
         noexcept(std::is_nothrow_move_constructible_v<T> &&
                  std::is_nothrow_move_assignable_v<T>)
-        requires std::movable<T>
+        requires std::move_constructible<T>
     {
         if (engaged_) {
             if (other.engaged_) {
-                item_ = std::move(other.item_);
+                if constexpr (std::is_move_assignable_v<T>) {
+                    item_ = std::move(other).item_;
+                } else {
+                    reset();
+                    construct(std::move(other).item_);
+                }
             } else {
                 reset();
             }
@@ -1150,7 +1161,7 @@ class optional<T> {
     }
 
     constexpr optional& operator=(optional&&)
-        requires std::movable<T> &&
+        requires std::move_constructible<T> &&
                  std::is_trivially_move_assignable_v<T>
         = default;
 
@@ -1429,6 +1440,10 @@ class optional<T&> {
      */
     constexpr auto reset() -> void { ptr_ = nullptr; }
 
+    template <typename U = T>
+        requires requires(U& u) { test_fn(u); }
+    constexpr auto emplace(U& item) -> void { ptr_ = std::addressof(item); }
+
     /*
      * Monadic operations
      */
@@ -8408,8 +8423,8 @@ struct flatten_adaptor : inline_sequence_base<flatten_adaptor<Base>> {
         static constexpr auto satisfy(auto& self, cursor_type& cur) -> void
         {
             while (!flux::is_last(self.base_, cur.outer_cur)) {
-                self.inner_ = optional<InnerSeq>(flux::read_at(self.base_, cur.outer_cur));
-                cur.inner_cur = optional(flux::first(*self.inner_));
+                self.inner_.emplace(flux::read_at(self.base_, cur.outer_cur));
+                cur.inner_cur.emplace(flux::first(*self.inner_));
                 if (!flux::is_last(*self.inner_, *cur.inner_cur)) {
                     return;
                 }