[llvm] r175729 - Add move ctor/assignment to Optional<T>
David Blaikie
dblaikie at gmail.com
Wed Feb 20 23:55:39 PST 2013
Author: dblaikie
Date: Thu Feb 21 01:55:39 2013
New Revision: 175729
URL: http://llvm.org/viewvc/llvm-project?rev=175729&view=rev
Log:
Add move ctor/assignment to Optional<T>
Code review feedback for r175580 by Jordan Rose.
Modified:
llvm/trunk/include/llvm/ADT/Optional.h
llvm/trunk/unittests/ADT/OptionalTest.cpp
Modified: llvm/trunk/include/llvm/ADT/Optional.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/Optional.h?rev=175729&r1=175728&r2=175729&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/Optional.h (original)
+++ llvm/trunk/include/llvm/ADT/Optional.h Thu Feb 21 01:55:39 2013
@@ -46,12 +46,41 @@ public:
Optional(T &&y) : hasVal(true) {
new (storage.buffer) T(std::forward<T>(y));
}
+ 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;
+ }
#endif
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;
Modified: llvm/trunk/unittests/ADT/OptionalTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/ADT/OptionalTest.cpp?rev=175729&r1=175728&r2=175729&view=diff
==============================================================================
--- llvm/trunk/unittests/ADT/OptionalTest.cpp (original)
+++ llvm/trunk/unittests/ADT/OptionalTest.cpp Thu Feb 21 01:55:39 2013
@@ -40,6 +40,36 @@ unsigned NonDefaultConstructible::CopyCo
unsigned NonDefaultConstructible::Destructions = 0;
unsigned NonDefaultConstructible::CopyAssignments = 0;
+struct MoveOnly {
+ static unsigned MoveConstructions;
+ static unsigned Destructions;
+ static unsigned MoveAssignments;
+ int val;
+ explicit MoveOnly(int val) : val(val) {
+ }
+ MoveOnly(MoveOnly&& other) {
+ val = other.val;
+ ++MoveConstructions;
+ }
+ MoveOnly &operator=(MoveOnly&& other) {
+ val = other.val;
+ ++MoveAssignments;
+ return *this;
+ }
+ ~MoveOnly() {
+ ++Destructions;
+ }
+ static void ResetCounts() {
+ MoveConstructions = 0;
+ Destructions = 0;
+ MoveAssignments = 0;
+ }
+};
+
+unsigned MoveOnly::MoveConstructions = 0;
+unsigned MoveOnly::Destructions = 0;
+unsigned MoveOnly::MoveAssignments = 0;
+
// Test fixture
class OptionalTest : public testing::Test {
};
@@ -169,5 +199,84 @@ TEST_F(OptionalTest, NullCopyConstructio
EXPECT_EQ(0u, NonDefaultConstructible::Destructions);
}
+TEST_F(OptionalTest, MoveOnlyNull) {
+ MoveOnly::ResetCounts();
+ Optional<MoveOnly> O;
+ EXPECT_EQ(0u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(0u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyConstruction) {
+ MoveOnly::ResetCounts();
+ Optional<MoveOnly> O(MoveOnly(3));
+ EXPECT_TRUE((bool)O);
+ EXPECT_EQ(3, O->val);
+ EXPECT_EQ(1u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyMoveConstruction) {
+ Optional<MoveOnly> A(MoveOnly(3));
+ MoveOnly::ResetCounts();
+ Optional<MoveOnly> B(std::move(A));
+ EXPECT_FALSE((bool)A);
+ EXPECT_TRUE((bool)B);
+ EXPECT_EQ(3, B->val);
+ EXPECT_EQ(1u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyAssignment) {
+ MoveOnly::ResetCounts();
+ Optional<MoveOnly> O;
+ O = MoveOnly(3);
+ EXPECT_TRUE((bool)O);
+ EXPECT_EQ(3, O->val);
+ EXPECT_EQ(1u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyInitializingAssignment) {
+ Optional<MoveOnly> A(MoveOnly(3));
+ Optional<MoveOnly> B;
+ MoveOnly::ResetCounts();
+ B = std::move(A);
+ EXPECT_FALSE((bool)A);
+ EXPECT_TRUE((bool)B);
+ EXPECT_EQ(3, B->val);
+ EXPECT_EQ(1u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyNullingAssignment) {
+ Optional<MoveOnly> A;
+ Optional<MoveOnly> B(MoveOnly(3));
+ MoveOnly::ResetCounts();
+ B = std::move(A);
+ EXPECT_FALSE((bool)A);
+ EXPECT_FALSE((bool)B);
+ EXPECT_EQ(0u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(0u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
+TEST_F(OptionalTest, MoveOnlyAssigningAssignment) {
+ Optional<MoveOnly> A(MoveOnly(3));
+ Optional<MoveOnly> B(MoveOnly(4));
+ MoveOnly::ResetCounts();
+ B = std::move(A);
+ EXPECT_FALSE((bool)A);
+ EXPECT_TRUE((bool)B);
+ EXPECT_EQ(3, B->val);
+ EXPECT_EQ(0u, MoveOnly::MoveConstructions);
+ EXPECT_EQ(1u, MoveOnly::MoveAssignments);
+ EXPECT_EQ(1u, MoveOnly::Destructions);
+}
+
} // end anonymous namespace
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