#define LLVM_ADT_OPTIONAL_H
#include "llvm/ADT/None.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/Compiler.h"
#include <cassert>
-
-#if LLVM_HAS_RVALUE_REFERENCES
+#include <new>
#include <utility>
-#endif
namespace llvm {
AlignedCharArrayUnion<T> storage;
bool hasVal;
public:
+ typedef T value_type;
+
Optional(NoneType) : hasVal(false) {}
explicit Optional() : hasVal(false) {}
Optional(const T &y) : hasVal(true) {
new (storage.buffer) T(*O);
}
-#if LLVM_HAS_RVALUE_REFERENCES
Optional(T &&y) : hasVal(true) {
new (storage.buffer) T(std::forward<T>(y));
}
-#endif
+ Optional(Optional<T> &&O) : hasVal(O) {
+ if (O) {
+ new (storage.buffer) T(std::move(*O));
+ O.reset();
+ }
+ }
+ Optional &operator=(T &&y) {
+ if (hasVal)
+ **this = std::move(y);
+ else {
+ new (storage.buffer) T(std::move(y));
+ hasVal = true;
+ }
+ return *this;
+ }
+ Optional &operator=(Optional &&O) {
+ if (!O)
+ reset();
+ else {
+ *this = std::move(*O);
+ O.reset();
+ }
+ return *this;
+ }
+
+ /// Create a new object by constructing it in place with the given arguments.
+ template<typename ...ArgTypes>
+ void emplace(ArgTypes &&...Args) {
+ reset();
+ hasVal = true;
+ new (storage.buffer) T(std::forward<ArgTypes>(Args)...);
+ }
static inline Optional create(const T* y) {
return y ? Optional(*y) : Optional();
}
+ // FIXME: these assignments (& the equivalent const T&/const Optional& ctors)
+ // could be made more efficient by passing by value, possibly unifying them
+ // with the rvalue versions above - but this could place a different set of
+ // requirements (notably: the existence of a default ctor) when implemented
+ // in that way. Careful SFINAE to avoid such pitfalls would be required.
Optional &operator=(const T &y) {
if (hasVal)
**this = y;
const T& getValue() const LLVM_LVALUE_FUNCTION { assert(hasVal); return *getPointer(); }
T& getValue() LLVM_LVALUE_FUNCTION { assert(hasVal); return *getPointer(); }
- operator bool() const { return hasVal; }
+ explicit operator bool() const { return hasVal; }
bool hasValue() const { return hasVal; }
const T* operator->() const { return getPointer(); }
T* operator->() { return getPointer(); }
const T& operator*() const LLVM_LVALUE_FUNCTION { assert(hasVal); return *getPointer(); }
T& operator*() LLVM_LVALUE_FUNCTION { assert(hasVal); return *getPointer(); }
+ template <typename U>
+ LLVM_CONSTEXPR T getValueOr(U &&value) const LLVM_LVALUE_FUNCTION {
+ return hasValue() ? getValue() : std::forward<U>(value);
+ }
+
#if LLVM_HAS_RVALUE_REFERENCE_THIS
T&& getValue() && { assert(hasVal); return std::move(*getPointer()); }
T&& operator*() && { assert(hasVal); return std::move(*getPointer()); }
-#endif
-};
-
-template<typename T> struct simplify_type;
-template <typename T>
-struct simplify_type<const Optional<T> > {
- typedef const T* SimpleType;
- static SimpleType getSimplifiedValue(const Optional<T> &Val) {
- return Val.getPointer();
+ template <typename U>
+ T getValueOr(U &&value) && {
+ return hasValue() ? std::move(getValue()) : std::forward<U>(value);
}
+#endif
};
-template <typename T>
-struct simplify_type<Optional<T> >
- : public simplify_type<const Optional<T> > {};
+template <typename T> struct isPodLike;
+template <typename T> struct isPodLike<Optional<T> > {
+ // An Optional<T> is pod-like if T is.
+ static const bool value = isPodLike<T>::value;
+};
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
template<typename T, typename U>
void operator==(const Optional<T> &X, const Optional<U> &Y);
+template<typename T>
+bool operator==(const Optional<T> &X, NoneType) {
+ return !X.hasValue();
+}
+
+template<typename T>
+bool operator==(NoneType, const Optional<T> &X) {
+ return X == None;
+}
+
+template<typename T>
+bool operator!=(const Optional<T> &X, NoneType) {
+ return !(X == None);
+}
+
+template<typename T>
+bool operator!=(NoneType, const Optional<T> &X) {
+ return X != None;
+}
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.