#include <type_traits>
#include <utility>
-#include <folly/Launder.h>
#include <folly/Portability.h>
+#include <folly/Traits.h>
#include <folly/Utility.h>
+#include <folly/lang/Launder.h>
namespace folly {
}
template <class... Args>
- void emplace(Args&&... args) {
+ Value& emplace(Args&&... args) {
clear();
- storage_.construct(std::forward<Args>(args)...);
+ return storage_.construct(std::forward<Args>(args)...);
+ }
+
+ template <class U, class... Args>
+ typename std::enable_if<
+ std::is_constructible<Value, std::initializer_list<U>&, Args&&...>::value,
+ Value&>::type
+ emplace(std::initializer_list<U> ilist, Args&&... args) {
+ clear();
+ return storage_.construct(ilist, std::forward<Args>(args)...);
}
- void clear() {
+ void reset() noexcept {
storage_.clear();
}
+ void clear() noexcept {
+ reset();
+ }
+
+ void swap(Optional& that) noexcept(IsNothrowSwappable<Value>::value) {
+ if (hasValue() && that.hasValue()) {
+ using std::swap;
+ swap(value(), that.value());
+ } else if (hasValue()) {
+ that.emplace(std::move(value()));
+ reset();
+ } else if (that.hasValue()) {
+ emplace(std::move(that.value()));
+ that.reset();
+ }
+ }
+
FOLLY_CPP14_CONSTEXPR const Value& value() const & {
require_value();
return *storage_.value_pointer();
}
Value* get_pointer() && = delete;
- FOLLY_CPP14_CONSTEXPR bool hasValue() const noexcept {
+ FOLLY_CPP14_CONSTEXPR bool has_value() const noexcept {
return storage_.hasValue();
}
+ FOLLY_CPP14_CONSTEXPR bool hasValue() const noexcept {
+ return has_value();
+ }
+
FOLLY_CPP14_CONSTEXPR explicit operator bool() const noexcept {
- return hasValue();
+ return has_value();
}
FOLLY_CPP14_CONSTEXPR const Value& operator*() const & {
}
template <class... Args>
- void construct(Args&&... args) {
+ Value& construct(Args&&... args) {
new (raw_pointer()) Value(std::forward<Args>(args)...);
this->hasValue_ = true;
+ return *launder(reinterpret_cast<Value*>(this->value_));
}
private:
}
template <class T>
-void swap(Optional<T>& a, Optional<T>& b) {
- if (a.hasValue() && b.hasValue()) {
- // both full
- using std::swap;
- swap(a.value(), b.value());
- } else if (a.hasValue() || b.hasValue()) {
- std::swap(a, b); // fall back to default implementation if they're mixed.
- }
+void swap(Optional<T>& a, Optional<T>& b) noexcept(noexcept(a.swap(b))) {
+ a.swap(b);
}
template <class T, class Opt = Optional<typename std::decay<T>::type>>
struct coroutine_traits<folly::Optional<Value>, Args...> {
using promise_type = folly::detail::OptionalPromise<Value>;
};
-} // experimental
+} // namespace experimental
FOLLY_NAMESPACE_STD_END
#endif // FOLLY_HAS_COROUTINES