#ifndef LLVM_ADT_OPTIONAL_H
#define LLVM_ADT_OPTIONAL_H
-#include "llvm/Support/Compiler.h"
+#include "llvm/ADT/None.h"
#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/Compiler.h"
#include <cassert>
-
-#if LLVM_HAS_RVALUE_REFERENCES
#include <utility>
-#endif
namespace llvm {
AlignedCharArrayUnion<T> storage;
bool hasVal;
public:
+ Optional(NoneType) : hasVal(false) {}
explicit Optional() : hasVal(false) {}
Optional(const T &y) : hasVal(true) {
new (storage.buffer) T(y);
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;
+ }
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;
~Optional() {
reset();
}
-
+
const T* getPointer() const { assert(hasVal); return reinterpret_cast<const T*>(storage.buffer); }
T* getPointer() { assert(hasVal); return reinterpret_cast<T*>(storage.buffer); }
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; }
+ LLVM_EXPLICIT operator bool() const { return hasVal; }
bool hasValue() const { return hasVal; }
const T* operator->() const { return getPointer(); }
T* operator->() { return 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 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;
};
-template <typename T>
-struct simplify_type<Optional<T> >
- : public simplify_type<const Optional<T> > {};
-
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator==(const Optional<T> &X, const Optional<U> &Y);
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator!=(const Optional<T> &X, const Optional<U> &Y);
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator<(const Optional<T> &X, const Optional<U> &Y);
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator<=(const Optional<T> &X, const Optional<U> &Y);
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator>=(const Optional<T> &X, const Optional<U> &Y);
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
-/// This routine will never be defined. It returns \c void to help diagnose
+/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator>(const Optional<T> &X, const Optional<U> &Y);