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-rw-r--r--mfbt/tests/TestMaybe.cpp1477
1 files changed, 1477 insertions, 0 deletions
diff --git a/mfbt/tests/TestMaybe.cpp b/mfbt/tests/TestMaybe.cpp
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+++ b/mfbt/tests/TestMaybe.cpp
@@ -0,0 +1,1477 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <type_traits>
+#include <utility>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Compiler.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/TemplateLib.h"
+#include "mozilla/Types.h"
+#include "mozilla/UniquePtr.h"
+
+using mozilla::Maybe;
+using mozilla::Nothing;
+using mozilla::Some;
+using mozilla::SomeRef;
+using mozilla::ToMaybe;
+using mozilla::ToMaybeRef;
+
+#define RUN_TEST(t) \
+ do { \
+ bool cond = (t()); \
+ if (!cond) return 1; \
+ cond = AllDestructorsWereCalled(); \
+ MOZ_ASSERT(cond, "Failed to destroy all objects during test: " #t); \
+ if (!cond) return 1; \
+ } while (false)
+
+enum Status {
+ eWasDefaultConstructed,
+ eWasConstructed,
+ eWasCopyConstructed,
+ eWasMoveConstructed,
+ eWasConstMoveConstructed,
+ eWasAssigned,
+ eWasCopyAssigned,
+ eWasMoveAssigned,
+ eWasCopiedFrom,
+ eWasMovedFrom,
+ eWasConstMovedFrom,
+};
+
+static size_t sUndestroyedObjects = 0;
+
+static bool AllDestructorsWereCalled() { return sUndestroyedObjects == 0; }
+
+struct BasicValue {
+ BasicValue() : mStatus(eWasDefaultConstructed), mTag(0) {
+ ++sUndestroyedObjects;
+ }
+
+ explicit BasicValue(int aTag) : mStatus(eWasConstructed), mTag(aTag) {
+ ++sUndestroyedObjects;
+ }
+
+ BasicValue(const BasicValue& aOther)
+ : mStatus(eWasCopyConstructed), mTag(aOther.mTag) {
+ ++sUndestroyedObjects;
+ }
+
+ BasicValue(BasicValue&& aOther)
+ : mStatus(eWasMoveConstructed), mTag(aOther.mTag) {
+ ++sUndestroyedObjects;
+ aOther.mStatus = eWasMovedFrom;
+ aOther.mTag = 0;
+ }
+
+ BasicValue(const BasicValue&& aOther)
+ : mStatus(eWasConstMoveConstructed), mTag(aOther.mTag) {
+ ++sUndestroyedObjects;
+ aOther.mStatus = eWasConstMovedFrom;
+ }
+
+ ~BasicValue() { --sUndestroyedObjects; }
+
+ BasicValue& operator=(const BasicValue& aOther) {
+ mStatus = eWasCopyAssigned;
+ mTag = aOther.mTag;
+ return *this;
+ }
+
+ BasicValue& operator=(BasicValue&& aOther) {
+ mStatus = eWasMoveAssigned;
+ mTag = aOther.mTag;
+ aOther.mStatus = eWasMovedFrom;
+ aOther.mTag = 0;
+ return *this;
+ }
+
+ bool operator==(const BasicValue& aOther) const {
+ return mTag == aOther.mTag;
+ }
+
+ bool operator<(const BasicValue& aOther) const { return mTag < aOther.mTag; }
+
+ Status GetStatus() const { return mStatus; }
+ void SetTag(int aValue) { mTag = aValue; }
+ int GetTag() const { return mTag; }
+
+ private:
+ mutable Status mStatus;
+ int mTag;
+};
+
+struct UncopyableValue {
+ UncopyableValue() : mStatus(eWasDefaultConstructed) { ++sUndestroyedObjects; }
+
+ UncopyableValue(UncopyableValue&& aOther) : mStatus(eWasMoveConstructed) {
+ ++sUndestroyedObjects;
+ aOther.mStatus = eWasMovedFrom;
+ }
+
+ ~UncopyableValue() { --sUndestroyedObjects; }
+
+ UncopyableValue& operator=(UncopyableValue&& aOther) {
+ mStatus = eWasMoveAssigned;
+ aOther.mStatus = eWasMovedFrom;
+ return *this;
+ }
+
+ Status GetStatus() { return mStatus; }
+
+ private:
+ UncopyableValue(const UncopyableValue& aOther) = delete;
+ UncopyableValue& operator=(const UncopyableValue& aOther) = delete;
+
+ Status mStatus;
+};
+
+struct UnmovableValue {
+ UnmovableValue() : mStatus(eWasDefaultConstructed) { ++sUndestroyedObjects; }
+
+ UnmovableValue(const UnmovableValue& aOther) : mStatus(eWasCopyConstructed) {
+ ++sUndestroyedObjects;
+ }
+
+ ~UnmovableValue() { --sUndestroyedObjects; }
+
+ UnmovableValue& operator=(const UnmovableValue& aOther) {
+ mStatus = eWasCopyAssigned;
+ return *this;
+ }
+
+ Status GetStatus() { return mStatus; }
+
+ UnmovableValue(UnmovableValue&& aOther) = delete;
+ UnmovableValue& operator=(UnmovableValue&& aOther) = delete;
+
+ private:
+ Status mStatus;
+};
+
+struct UncopyableUnmovableValue {
+ UncopyableUnmovableValue() : mStatus(eWasDefaultConstructed) {
+ ++sUndestroyedObjects;
+ }
+
+ explicit UncopyableUnmovableValue(int) : mStatus(eWasConstructed) {
+ ++sUndestroyedObjects;
+ }
+
+ ~UncopyableUnmovableValue() { --sUndestroyedObjects; }
+
+ Status GetStatus() const { return mStatus; }
+
+ private:
+ UncopyableUnmovableValue(const UncopyableUnmovableValue& aOther) = delete;
+ UncopyableUnmovableValue& operator=(const UncopyableUnmovableValue& aOther) =
+ delete;
+ UncopyableUnmovableValue(UncopyableUnmovableValue&& aOther) = delete;
+ UncopyableUnmovableValue& operator=(UncopyableUnmovableValue&& aOther) =
+ delete;
+
+ Status mStatus;
+};
+
+static_assert(std::is_trivially_destructible_v<Maybe<int>>);
+static_assert(std::is_trivially_copy_constructible_v<Maybe<int>>);
+static_assert(std::is_trivially_copy_assignable_v<Maybe<int>>);
+
+static_assert(42 == Some(42).value());
+static_assert(42 == Some(42).valueOr(43));
+static_assert(42 == Maybe<int>{}.valueOr(42));
+static_assert(42 == Some(42).valueOrFrom([] { return 43; }));
+static_assert(42 == Maybe<int>{}.valueOrFrom([] { return 42; }));
+static_assert(Some(43) == [] {
+ auto val = Some(42);
+ val.apply([](int& val) { val += 1; });
+ return val;
+}());
+static_assert(Some(43) == Some(42).map([](int val) { return val + 1; }));
+static_assert(Maybe<int>(std::in_place, 43) ==
+ Maybe<int>(std::in_place, 42).map([](int val) {
+ return val + 1;
+ }));
+
+struct TriviallyDestructible {
+ TriviallyDestructible() { // not trivially constructible
+ }
+};
+
+static_assert(std::is_trivially_destructible_v<Maybe<TriviallyDestructible>>);
+
+struct UncopyableValueLiteralType {
+ explicit constexpr UncopyableValueLiteralType(int aValue) : mValue{aValue} {}
+
+ UncopyableValueLiteralType(UncopyableValueLiteralType&&) = default;
+ UncopyableValueLiteralType& operator=(UncopyableValueLiteralType&&) = default;
+
+ int mValue;
+};
+
+static_assert(
+ std::is_trivially_destructible_v<Maybe<UncopyableValueLiteralType>>);
+static_assert(!std::is_copy_constructible_v<Maybe<UncopyableValueLiteralType>>);
+static_assert(!std::is_copy_assignable_v<Maybe<UncopyableValueLiteralType>>);
+static_assert(std::is_move_constructible_v<Maybe<UncopyableValueLiteralType>>);
+static_assert(std::is_move_assignable_v<Maybe<UncopyableValueLiteralType>>);
+
+constexpr Maybe<UncopyableValueLiteralType> someUncopyable =
+ Some(UncopyableValueLiteralType{42});
+static_assert(someUncopyable.isSome());
+static_assert(42 == someUncopyable->mValue);
+
+constexpr Maybe<UncopyableValueLiteralType> someUncopyableAssigned = [] {
+ auto res = Maybe<UncopyableValueLiteralType>{};
+ res = Some(UncopyableValueLiteralType{42});
+ return res;
+}();
+static_assert(someUncopyableAssigned.isSome());
+static_assert(42 == someUncopyableAssigned->mValue);
+
+static bool TestBasicFeatures() {
+ // Check that a Maybe<T> is initialized to Nothing.
+ Maybe<BasicValue> mayValue;
+ static_assert(std::is_same_v<BasicValue, decltype(mayValue)::ValueType>,
+ "Should have BasicValue ValueType");
+ MOZ_RELEASE_ASSERT(!mayValue);
+ MOZ_RELEASE_ASSERT(!mayValue.isSome());
+ MOZ_RELEASE_ASSERT(mayValue.isNothing());
+
+ // Check that emplace() default constructs and the accessors work.
+ mayValue.emplace();
+ MOZ_RELEASE_ASSERT(mayValue);
+ MOZ_RELEASE_ASSERT(mayValue.isSome());
+ MOZ_RELEASE_ASSERT(!mayValue.isNothing());
+ MOZ_RELEASE_ASSERT(*mayValue == BasicValue());
+ static_assert(std::is_same_v<BasicValue&, decltype(*mayValue)>,
+ "operator*() should return a BasicValue&");
+ MOZ_RELEASE_ASSERT(mayValue.value() == BasicValue());
+ static_assert(std::is_same_v<BasicValue, decltype(mayValue.value())>,
+ "value() should return a BasicValue");
+ MOZ_RELEASE_ASSERT(mayValue.ref() == BasicValue());
+ static_assert(std::is_same_v<BasicValue&, decltype(mayValue.ref())>,
+ "ref() should return a BasicValue&");
+ MOZ_RELEASE_ASSERT(mayValue.ptr() != nullptr);
+ static_assert(std::is_same_v<BasicValue*, decltype(mayValue.ptr())>,
+ "ptr() should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(mayValue->GetStatus() == eWasDefaultConstructed);
+
+ // Check that reset() works.
+ mayValue.reset();
+ MOZ_RELEASE_ASSERT(!mayValue);
+ MOZ_RELEASE_ASSERT(!mayValue.isSome());
+ MOZ_RELEASE_ASSERT(mayValue.isNothing());
+
+ // Check that emplace(T1) calls the correct constructor.
+ mayValue.emplace(1);
+ MOZ_RELEASE_ASSERT(mayValue);
+ MOZ_RELEASE_ASSERT(mayValue->GetStatus() == eWasConstructed);
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 1);
+ mayValue.reset();
+ MOZ_RELEASE_ASSERT(!mayValue);
+
+ {
+ // Check that Maybe(std::in_place, T1) calls the correct constructor.
+ const auto mayValueConstructed = Maybe<BasicValue>(std::in_place, 1);
+ MOZ_RELEASE_ASSERT(mayValueConstructed);
+ MOZ_RELEASE_ASSERT(mayValueConstructed->GetStatus() == eWasConstructed);
+ MOZ_RELEASE_ASSERT(mayValueConstructed->GetTag() == 1);
+ }
+
+ // Check that Some() and Nothing() work.
+ mayValue = Some(BasicValue(2));
+ MOZ_RELEASE_ASSERT(mayValue);
+ MOZ_RELEASE_ASSERT(mayValue->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 2);
+ mayValue = Nothing();
+ MOZ_RELEASE_ASSERT(!mayValue);
+
+ // Check that the accessors work through a const ref.
+ mayValue.emplace();
+ const Maybe<BasicValue>& mayValueCRef = mayValue;
+ MOZ_RELEASE_ASSERT(mayValueCRef);
+ MOZ_RELEASE_ASSERT(mayValueCRef.isSome());
+ MOZ_RELEASE_ASSERT(!mayValueCRef.isNothing());
+ MOZ_RELEASE_ASSERT(*mayValueCRef == BasicValue());
+ static_assert(std::is_same_v<const BasicValue&, decltype(*mayValueCRef)>,
+ "operator*() should return a BasicValue");
+ MOZ_RELEASE_ASSERT(mayValueCRef.value() == BasicValue());
+ static_assert(std::is_same_v<BasicValue, decltype(mayValueCRef.value())>,
+ "value() should return a BasicValue");
+ MOZ_RELEASE_ASSERT(mayValueCRef.ref() == BasicValue());
+ static_assert(std::is_same_v<const BasicValue&, decltype(mayValueCRef.ref())>,
+ "ref() should return a const BasicValue&");
+ MOZ_RELEASE_ASSERT(mayValueCRef.ptr() != nullptr);
+ static_assert(std::is_same_v<const BasicValue*, decltype(mayValueCRef.ptr())>,
+ "ptr() should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(mayValueCRef->GetStatus() == eWasDefaultConstructed);
+ mayValue.reset();
+
+ // Check that we can create and reference Maybe<const Type>.
+ Maybe<const BasicValue> mayCValue1 = Some(BasicValue(5));
+ MOZ_RELEASE_ASSERT(mayCValue1);
+ MOZ_RELEASE_ASSERT(mayCValue1.isSome());
+ MOZ_RELEASE_ASSERT(*mayCValue1 == BasicValue(5));
+ const Maybe<const BasicValue>& mayCValue1Ref = mayCValue1;
+ MOZ_RELEASE_ASSERT(mayCValue1Ref == mayCValue1);
+ MOZ_RELEASE_ASSERT(*mayCValue1Ref == BasicValue(5));
+ Maybe<const BasicValue> mayCValue2;
+ mayCValue2.emplace(6);
+ MOZ_RELEASE_ASSERT(mayCValue2);
+ MOZ_RELEASE_ASSERT(mayCValue2.isSome());
+ MOZ_RELEASE_ASSERT(*mayCValue2 == BasicValue(6));
+
+ // Check that accessors work through rvalue-references.
+ MOZ_RELEASE_ASSERT(Some(BasicValue()));
+ MOZ_RELEASE_ASSERT(Some(BasicValue()).isSome());
+ MOZ_RELEASE_ASSERT(!Some(BasicValue()).isNothing());
+ MOZ_RELEASE_ASSERT(*Some(BasicValue()) == BasicValue());
+ static_assert(std::is_same_v<BasicValue&&, decltype(*Some(BasicValue()))>,
+ "operator*() should return a BasicValue&&");
+ MOZ_RELEASE_ASSERT(Some(BasicValue()).value() == BasicValue());
+ static_assert(
+ std::is_same_v<BasicValue, decltype(Some(BasicValue()).value())>,
+ "value() should return a BasicValue");
+ MOZ_RELEASE_ASSERT(Some(BasicValue()).ref() == BasicValue());
+ static_assert(
+ std::is_same_v<BasicValue&&, decltype(Some(BasicValue()).ref())>,
+ "ref() should return a BasicValue&&");
+ MOZ_RELEASE_ASSERT(Some(BasicValue()).ptr() != nullptr);
+ static_assert(std::is_same_v<BasicValue*, decltype(Some(BasicValue()).ptr())>,
+ "ptr() should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(Some(BasicValue())->GetStatus() == eWasMoveConstructed);
+
+ // Check that accessors work through const-rvalue-references.
+ auto MakeConstMaybe = []() -> const Maybe<BasicValue> {
+ return Some(BasicValue());
+ };
+ MOZ_RELEASE_ASSERT(MakeConstMaybe());
+ MOZ_RELEASE_ASSERT(MakeConstMaybe().isSome());
+ MOZ_RELEASE_ASSERT(!MakeConstMaybe().isNothing());
+ MOZ_RELEASE_ASSERT(*MakeConstMaybe() == BasicValue());
+ static_assert(std::is_same_v<const BasicValue&&, decltype(*MakeConstMaybe())>,
+ "operator*() should return a const BasicValue&&");
+ MOZ_RELEASE_ASSERT(MakeConstMaybe().value() == BasicValue());
+ static_assert(std::is_same_v<BasicValue, decltype(MakeConstMaybe().value())>,
+ "value() should return a BasicValue");
+ MOZ_RELEASE_ASSERT(MakeConstMaybe().ref() == BasicValue());
+ static_assert(
+ std::is_same_v<const BasicValue&&, decltype(MakeConstMaybe().ref())>,
+ "ref() should return a const BasicValue&&");
+ MOZ_RELEASE_ASSERT(MakeConstMaybe().ptr() != nullptr);
+ static_assert(
+ std::is_same_v<const BasicValue*, decltype(MakeConstMaybe().ptr())>,
+ "ptr() should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(MakeConstMaybe()->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(BasicValue(*MakeConstMaybe()).GetStatus() ==
+ eWasConstMoveConstructed);
+
+ // Check that take works
+ mayValue = Some(BasicValue(6));
+ Maybe taken = mayValue.take();
+ MOZ_RELEASE_ASSERT(taken->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(taken == Some(BasicValue(6)));
+ MOZ_RELEASE_ASSERT(!mayValue.isSome());
+ MOZ_RELEASE_ASSERT(mayValue.take() == Nothing());
+
+ // Check that extract works
+ mayValue = Some(BasicValue(7));
+ BasicValue extracted = mayValue.extract();
+ MOZ_RELEASE_ASSERT(extracted.GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(extracted == BasicValue(7));
+ MOZ_RELEASE_ASSERT(!mayValue.isSome());
+
+ return true;
+}
+
+template <typename T>
+static void TestCopyMaybe() {
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ Maybe<T> dstCopyConstructed = src;
+
+ MOZ_RELEASE_ASSERT(2 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstCopyConstructed->GetStatus() == eWasCopyConstructed);
+ }
+
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ Maybe<T> dstCopyAssigned;
+ dstCopyAssigned = src;
+
+ MOZ_RELEASE_ASSERT(2 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstCopyAssigned->GetStatus() == eWasCopyConstructed);
+ }
+}
+
+template <typename T>
+static void TestMoveMaybe() {
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ Maybe<T> dstMoveConstructed = std::move(src);
+
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstMoveConstructed->GetStatus() == eWasMoveConstructed);
+ }
+
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ Maybe<T> dstMoveAssigned;
+ dstMoveAssigned = std::move(src);
+
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstMoveAssigned->GetStatus() == eWasMoveConstructed);
+ }
+
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ Maybe<T> dstMoveConstructed = src.take();
+
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstMoveConstructed->GetStatus() == eWasMoveConstructed);
+ }
+
+ {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ Maybe<T> src = Some(T());
+ T dstMoveConstructed = src.extract();
+
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(dstMoveConstructed.GetStatus() == eWasMoveConstructed);
+ }
+}
+
+static bool TestCopyAndMove() {
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ {
+ // Check that we get moves when possible for types that can support both
+ // moves and copies.
+ {
+ Maybe<BasicValue> mayBasicValue = Some(BasicValue(1));
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetTag() == 1);
+ mayBasicValue = Some(BasicValue(2));
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetStatus() == eWasMoveAssigned);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetTag() == 2);
+ mayBasicValue.reset();
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+ mayBasicValue.emplace(BasicValue(3));
+ MOZ_RELEASE_ASSERT(1 == sUndestroyedObjects);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetTag() == 3);
+
+ // Check that we get copies when moves aren't possible.
+ Maybe<BasicValue> mayBasicValue2 = Some(*mayBasicValue);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetStatus() == eWasCopyConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetTag() == 3);
+ mayBasicValue->SetTag(4);
+ mayBasicValue2 = mayBasicValue;
+ // This test should work again when we fix bug 1052940.
+ // MOZ_RELEASE_ASSERT(mayBasicValue2->GetStatus() == eWasCopyAssigned);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetTag() == 4);
+ mayBasicValue->SetTag(5);
+ mayBasicValue2.reset();
+ mayBasicValue2.emplace(*mayBasicValue);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetStatus() == eWasCopyConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetTag() == 5);
+
+ // Check that std::move() works. (Another sanity check for move support.)
+ Maybe<BasicValue> mayBasicValue3 = Some(std::move(*mayBasicValue));
+ MOZ_RELEASE_ASSERT(mayBasicValue3->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue3->GetTag() == 5);
+ MOZ_RELEASE_ASSERT(mayBasicValue->GetStatus() == eWasMovedFrom);
+ mayBasicValue2->SetTag(6);
+ mayBasicValue3 = Some(std::move(*mayBasicValue2));
+ MOZ_RELEASE_ASSERT(mayBasicValue3->GetStatus() == eWasMoveAssigned);
+ MOZ_RELEASE_ASSERT(mayBasicValue3->GetTag() == 6);
+ MOZ_RELEASE_ASSERT(mayBasicValue2->GetStatus() == eWasMovedFrom);
+ Maybe<BasicValue> mayBasicValue4;
+ mayBasicValue4.emplace(std::move(*mayBasicValue3));
+ MOZ_RELEASE_ASSERT(mayBasicValue4->GetStatus() == eWasMoveConstructed);
+ MOZ_RELEASE_ASSERT(mayBasicValue4->GetTag() == 6);
+ MOZ_RELEASE_ASSERT(mayBasicValue3->GetStatus() == eWasMovedFrom);
+ }
+
+ TestCopyMaybe<BasicValue>();
+ TestMoveMaybe<BasicValue>();
+ }
+
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ {
+ // Check that we always get copies for types that don't support moves.
+ {
+ Maybe<UnmovableValue> mayUnmovableValue = Some(UnmovableValue());
+ MOZ_RELEASE_ASSERT(mayUnmovableValue->GetStatus() == eWasCopyConstructed);
+ mayUnmovableValue = Some(UnmovableValue());
+ MOZ_RELEASE_ASSERT(mayUnmovableValue->GetStatus() == eWasCopyAssigned);
+ mayUnmovableValue.reset();
+ mayUnmovableValue.emplace(UnmovableValue());
+ MOZ_RELEASE_ASSERT(mayUnmovableValue->GetStatus() == eWasCopyConstructed);
+ }
+
+ TestCopyMaybe<UnmovableValue>();
+
+ static_assert(std::is_copy_constructible_v<Maybe<UnmovableValue>>);
+ static_assert(std::is_copy_assignable_v<Maybe<UnmovableValue>>);
+ // XXX Why do these static_asserts not hold?
+ // static_assert(!std::is_move_constructible_v<Maybe<UnmovableValue>>);
+ // static_assert(!std::is_move_assignable_v<Maybe<UnmovableValue>>);
+ }
+
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ {
+ // Check that types that only support moves, but not copies, work.
+ {
+ Maybe<UncopyableValue> mayUncopyableValue = Some(UncopyableValue());
+ MOZ_RELEASE_ASSERT(mayUncopyableValue->GetStatus() ==
+ eWasMoveConstructed);
+ mayUncopyableValue = Some(UncopyableValue());
+ MOZ_RELEASE_ASSERT(mayUncopyableValue->GetStatus() == eWasMoveAssigned);
+ mayUncopyableValue.reset();
+ mayUncopyableValue.emplace(UncopyableValue());
+ MOZ_RELEASE_ASSERT(mayUncopyableValue->GetStatus() ==
+ eWasMoveConstructed);
+ mayUncopyableValue = Nothing();
+ }
+
+ TestMoveMaybe<BasicValue>();
+
+ static_assert(!std::is_copy_constructible_v<Maybe<UncopyableValue>>);
+ static_assert(!std::is_copy_assignable_v<Maybe<UncopyableValue>>);
+ static_assert(std::is_move_constructible_v<Maybe<UncopyableValue>>);
+ static_assert(std::is_move_assignable_v<Maybe<UncopyableValue>>);
+ }
+
+ MOZ_RELEASE_ASSERT(0 == sUndestroyedObjects);
+
+ { // Check that types that support neither moves or copies work.
+ {
+ const auto mayUncopyableUnmovableValueConstructed =
+ Maybe<UncopyableUnmovableValue>{std::in_place};
+ MOZ_RELEASE_ASSERT(mayUncopyableUnmovableValueConstructed->GetStatus() ==
+ eWasDefaultConstructed);
+ }
+
+ Maybe<UncopyableUnmovableValue> mayUncopyableUnmovableValue;
+ mayUncopyableUnmovableValue.emplace();
+ MOZ_RELEASE_ASSERT(mayUncopyableUnmovableValue->GetStatus() ==
+ eWasDefaultConstructed);
+ mayUncopyableUnmovableValue.reset();
+ mayUncopyableUnmovableValue.emplace(0);
+ MOZ_RELEASE_ASSERT(mayUncopyableUnmovableValue->GetStatus() ==
+ eWasConstructed);
+ mayUncopyableUnmovableValue = Nothing();
+
+ static_assert(
+ !std::is_copy_constructible_v<Maybe<UncopyableUnmovableValue>>);
+ static_assert(!std::is_copy_assignable_v<Maybe<UncopyableUnmovableValue>>);
+ static_assert(
+ !std::is_move_constructible_v<Maybe<UncopyableUnmovableValue>>);
+ static_assert(!std::is_move_assignable_v<Maybe<UncopyableUnmovableValue>>);
+ }
+
+ {
+ // Test copy and move with a trivially copyable and trivially destructible
+ // type.
+ {
+ constexpr Maybe<int> src = Some(42);
+ constexpr Maybe<int> dstCopyConstructed = src;
+
+ static_assert(src.isSome());
+ static_assert(dstCopyConstructed.isSome());
+ static_assert(42 == *src);
+ static_assert(42 == *dstCopyConstructed);
+ static_assert(42 == dstCopyConstructed.value());
+ }
+
+ {
+ const Maybe<int> src = Some(42);
+ Maybe<int> dstCopyAssigned;
+ dstCopyAssigned = src;
+
+ MOZ_RELEASE_ASSERT(src.isSome());
+ MOZ_RELEASE_ASSERT(dstCopyAssigned.isSome());
+ MOZ_RELEASE_ASSERT(42 == *src);
+ MOZ_RELEASE_ASSERT(42 == *dstCopyAssigned);
+ }
+
+ {
+ Maybe<int> src = Some(42);
+ const Maybe<int> dstMoveConstructed = std::move(src);
+
+ MOZ_RELEASE_ASSERT(!src.isSome());
+ MOZ_RELEASE_ASSERT(dstMoveConstructed.isSome());
+ MOZ_RELEASE_ASSERT(42 == *dstMoveConstructed);
+ }
+
+ {
+ Maybe<int> src = Some(42);
+ Maybe<int> dstMoveAssigned;
+ dstMoveAssigned = std::move(src);
+
+ MOZ_RELEASE_ASSERT(!src.isSome());
+ MOZ_RELEASE_ASSERT(dstMoveAssigned.isSome());
+ MOZ_RELEASE_ASSERT(42 == *dstMoveAssigned);
+ }
+ }
+
+ return true;
+}
+
+static BasicValue* sStaticBasicValue = nullptr;
+
+static BasicValue MakeBasicValue() { return BasicValue(9); }
+
+static BasicValue& MakeBasicValueRef() { return *sStaticBasicValue; }
+
+static BasicValue* MakeBasicValuePtr() { return sStaticBasicValue; }
+
+static bool TestFunctionalAccessors() {
+ BasicValue value(9);
+ sStaticBasicValue = new BasicValue(9);
+
+ // Check that the 'some' case of functional accessors works.
+ Maybe<BasicValue> someValue = Some(BasicValue(3));
+ MOZ_RELEASE_ASSERT(someValue.valueOr(value) == BasicValue(3));
+ static_assert(std::is_same_v<BasicValue, decltype(someValue.valueOr(value))>,
+ "valueOr should return a BasicValue");
+ MOZ_RELEASE_ASSERT(someValue.valueOrFrom(&MakeBasicValue) == BasicValue(3));
+ static_assert(
+ std::is_same_v<BasicValue,
+ decltype(someValue.valueOrFrom(&MakeBasicValue))>,
+ "valueOrFrom should return a BasicValue");
+ MOZ_RELEASE_ASSERT(someValue.ptrOr(&value) != &value);
+ static_assert(std::is_same_v<BasicValue*, decltype(someValue.ptrOr(&value))>,
+ "ptrOr should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(*someValue.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(3));
+ static_assert(
+ std::is_same_v<BasicValue*,
+ decltype(someValue.ptrOrFrom(&MakeBasicValuePtr))>,
+ "ptrOrFrom should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(someValue.refOr(value) == BasicValue(3));
+ static_assert(std::is_same_v<BasicValue&, decltype(someValue.refOr(value))>,
+ "refOr should return a BasicValue&");
+ MOZ_RELEASE_ASSERT(someValue.refOrFrom(&MakeBasicValueRef) == BasicValue(3));
+ static_assert(
+ std::is_same_v<BasicValue&,
+ decltype(someValue.refOrFrom(&MakeBasicValueRef))>,
+ "refOrFrom should return a BasicValue&");
+
+ // Check that the 'some' case works through a const reference.
+ const Maybe<BasicValue>& someValueCRef = someValue;
+ MOZ_RELEASE_ASSERT(someValueCRef.valueOr(value) == BasicValue(3));
+ static_assert(
+ std::is_same_v<BasicValue, decltype(someValueCRef.valueOr(value))>,
+ "valueOr should return a BasicValue");
+ MOZ_RELEASE_ASSERT(someValueCRef.valueOrFrom(&MakeBasicValue) ==
+ BasicValue(3));
+ static_assert(
+ std::is_same_v<BasicValue,
+ decltype(someValueCRef.valueOrFrom(&MakeBasicValue))>,
+ "valueOrFrom should return a BasicValue");
+ MOZ_RELEASE_ASSERT(someValueCRef.ptrOr(&value) != &value);
+ static_assert(
+ std::is_same_v<const BasicValue*, decltype(someValueCRef.ptrOr(&value))>,
+ "ptrOr should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(*someValueCRef.ptrOrFrom(&MakeBasicValuePtr) ==
+ BasicValue(3));
+ static_assert(
+ std::is_same_v<const BasicValue*,
+ decltype(someValueCRef.ptrOrFrom(&MakeBasicValuePtr))>,
+ "ptrOrFrom should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(someValueCRef.refOr(value) == BasicValue(3));
+ static_assert(
+ std::is_same_v<const BasicValue&, decltype(someValueCRef.refOr(value))>,
+ "refOr should return a const BasicValue&");
+ MOZ_RELEASE_ASSERT(someValueCRef.refOrFrom(&MakeBasicValueRef) ==
+ BasicValue(3));
+ static_assert(
+ std::is_same_v<const BasicValue&,
+ decltype(someValueCRef.refOrFrom(&MakeBasicValueRef))>,
+ "refOrFrom should return a const BasicValue&");
+
+ // Check that the 'none' case of functional accessors works.
+ Maybe<BasicValue> noneValue;
+ MOZ_RELEASE_ASSERT(noneValue.valueOr(value) == BasicValue(9));
+ static_assert(std::is_same_v<BasicValue, decltype(noneValue.valueOr(value))>,
+ "valueOr should return a BasicValue");
+ MOZ_RELEASE_ASSERT(noneValue.valueOrFrom(&MakeBasicValue) == BasicValue(9));
+ static_assert(
+ std::is_same_v<BasicValue,
+ decltype(noneValue.valueOrFrom(&MakeBasicValue))>,
+ "valueOrFrom should return a BasicValue");
+ MOZ_RELEASE_ASSERT(noneValue.ptrOr(&value) == &value);
+ static_assert(std::is_same_v<BasicValue*, decltype(noneValue.ptrOr(&value))>,
+ "ptrOr should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(*noneValue.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(9));
+ static_assert(
+ std::is_same_v<BasicValue*,
+ decltype(noneValue.ptrOrFrom(&MakeBasicValuePtr))>,
+ "ptrOrFrom should return a BasicValue*");
+ MOZ_RELEASE_ASSERT(noneValue.refOr(value) == BasicValue(9));
+ static_assert(std::is_same_v<BasicValue&, decltype(noneValue.refOr(value))>,
+ "refOr should return a BasicValue&");
+ MOZ_RELEASE_ASSERT(noneValue.refOrFrom(&MakeBasicValueRef) == BasicValue(9));
+ static_assert(
+ std::is_same_v<BasicValue&,
+ decltype(noneValue.refOrFrom(&MakeBasicValueRef))>,
+ "refOrFrom should return a BasicValue&");
+
+ // Check that the 'none' case works through a const reference.
+ const Maybe<BasicValue>& noneValueCRef = noneValue;
+ MOZ_RELEASE_ASSERT(noneValueCRef.valueOr(value) == BasicValue(9));
+ static_assert(
+ std::is_same_v<BasicValue, decltype(noneValueCRef.valueOr(value))>,
+ "valueOr should return a BasicValue");
+ MOZ_RELEASE_ASSERT(noneValueCRef.valueOrFrom(&MakeBasicValue) ==
+ BasicValue(9));
+ static_assert(
+ std::is_same_v<BasicValue,
+ decltype(noneValueCRef.valueOrFrom(&MakeBasicValue))>,
+ "valueOrFrom should return a BasicValue");
+ MOZ_RELEASE_ASSERT(noneValueCRef.ptrOr(&value) == &value);
+ static_assert(
+ std::is_same_v<const BasicValue*, decltype(noneValueCRef.ptrOr(&value))>,
+ "ptrOr should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(*noneValueCRef.ptrOrFrom(&MakeBasicValuePtr) ==
+ BasicValue(9));
+ static_assert(
+ std::is_same_v<const BasicValue*,
+ decltype(noneValueCRef.ptrOrFrom(&MakeBasicValuePtr))>,
+ "ptrOrFrom should return a const BasicValue*");
+ MOZ_RELEASE_ASSERT(noneValueCRef.refOr(value) == BasicValue(9));
+ static_assert(
+ std::is_same_v<const BasicValue&, decltype(noneValueCRef.refOr(value))>,
+ "refOr should return a const BasicValue&");
+ MOZ_RELEASE_ASSERT(noneValueCRef.refOrFrom(&MakeBasicValueRef) ==
+ BasicValue(9));
+ static_assert(
+ std::is_same_v<const BasicValue&,
+ decltype(noneValueCRef.refOrFrom(&MakeBasicValueRef))>,
+ "refOrFrom should return a const BasicValue&");
+
+ // Clean up so the undestroyed objects count stays accurate.
+ delete sStaticBasicValue;
+ sStaticBasicValue = nullptr;
+
+ return true;
+}
+
+static bool gFunctionWasApplied = false;
+
+static void IncrementTag(BasicValue& aValue) {
+ gFunctionWasApplied = true;
+ aValue.SetTag(aValue.GetTag() + 1);
+}
+
+static void AccessValue(const BasicValue&) { gFunctionWasApplied = true; }
+
+struct IncrementTagFunctor {
+ IncrementTagFunctor() : mBy(1) {}
+
+ void operator()(BasicValue& aValue) {
+ aValue.SetTag(aValue.GetTag() + mBy.GetTag());
+ }
+
+ BasicValue mBy;
+};
+
+static bool TestApply() {
+ // Check that apply handles the 'Nothing' case.
+ gFunctionWasApplied = false;
+ Maybe<BasicValue> mayValue;
+ mayValue.apply(&IncrementTag);
+ mayValue.apply(&AccessValue);
+ MOZ_RELEASE_ASSERT(!gFunctionWasApplied);
+
+ // Check that apply handles the 'Some' case.
+ mayValue = Some(BasicValue(1));
+ mayValue.apply(&IncrementTag);
+ MOZ_RELEASE_ASSERT(gFunctionWasApplied);
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 2);
+ gFunctionWasApplied = false;
+ mayValue.apply(&AccessValue);
+ MOZ_RELEASE_ASSERT(gFunctionWasApplied);
+
+ // Check that apply works with a const reference.
+ const Maybe<BasicValue>& mayValueCRef = mayValue;
+ gFunctionWasApplied = false;
+ mayValueCRef.apply(&AccessValue);
+ MOZ_RELEASE_ASSERT(gFunctionWasApplied);
+
+ // Check that apply works with functors.
+ IncrementTagFunctor tagIncrementer;
+ MOZ_RELEASE_ASSERT(tagIncrementer.mBy.GetStatus() == eWasConstructed);
+ mayValue = Some(BasicValue(1));
+ mayValue.apply(tagIncrementer);
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 2);
+ MOZ_RELEASE_ASSERT(tagIncrementer.mBy.GetStatus() == eWasConstructed);
+
+ // Check that apply works with lambda expressions.
+ int32_t two = 2;
+ gFunctionWasApplied = false;
+ mayValue = Some(BasicValue(2));
+ mayValue.apply([&](BasicValue& aVal) { aVal.SetTag(aVal.GetTag() * two); });
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 4);
+ mayValue.apply([=](BasicValue& aVal) { aVal.SetTag(aVal.GetTag() * two); });
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 8);
+ mayValueCRef.apply(
+ [&](const BasicValue& aVal) { gFunctionWasApplied = true; });
+ MOZ_RELEASE_ASSERT(gFunctionWasApplied == true);
+
+ return true;
+}
+
+static int TimesTwo(const BasicValue& aValue) { return aValue.GetTag() * 2; }
+
+static int TimesTwoAndResetOriginal(BasicValue& aValue) {
+ int tag = aValue.GetTag();
+ aValue.SetTag(1);
+ return tag * 2;
+}
+
+struct MultiplyTagFunctor {
+ MultiplyTagFunctor() : mBy(2) {}
+
+ int operator()(BasicValue& aValue) { return aValue.GetTag() * mBy.GetTag(); }
+
+ BasicValue mBy;
+};
+
+static bool TestMap() {
+ // Check that map handles the 'Nothing' case.
+ Maybe<BasicValue> mayValue;
+ MOZ_RELEASE_ASSERT(mayValue.map(&TimesTwo) == Nothing());
+ static_assert(std::is_same_v<Maybe<int>, decltype(mayValue.map(&TimesTwo))>,
+ "map(TimesTwo) should return a Maybe<int>");
+ MOZ_RELEASE_ASSERT(mayValue.map(&TimesTwoAndResetOriginal) == Nothing());
+
+ // Check that map handles the 'Some' case.
+ mayValue = Some(BasicValue(2));
+ MOZ_RELEASE_ASSERT(mayValue.map(&TimesTwo) == Some(4));
+ MOZ_RELEASE_ASSERT(mayValue.map(&TimesTwoAndResetOriginal) == Some(4));
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 1);
+ mayValue = Some(BasicValue(2));
+
+ // Check that map works with a const reference.
+ mayValue->SetTag(2);
+ const Maybe<BasicValue>& mayValueCRef = mayValue;
+ MOZ_RELEASE_ASSERT(mayValueCRef.map(&TimesTwo) == Some(4));
+ static_assert(
+ std::is_same_v<Maybe<int>, decltype(mayValueCRef.map(&TimesTwo))>,
+ "map(TimesTwo) should return a Maybe<int>");
+
+ // Check that map works with functors.
+ MultiplyTagFunctor tagMultiplier;
+ MOZ_RELEASE_ASSERT(tagMultiplier.mBy.GetStatus() == eWasConstructed);
+ MOZ_RELEASE_ASSERT(mayValue.map(tagMultiplier) == Some(4));
+ MOZ_RELEASE_ASSERT(tagMultiplier.mBy.GetStatus() == eWasConstructed);
+
+ // Check that map works with lambda expressions.
+ int two = 2;
+ mayValue = Some(BasicValue(2));
+ Maybe<int> mappedValue =
+ mayValue.map([&](const BasicValue& aVal) { return aVal.GetTag() * two; });
+ MOZ_RELEASE_ASSERT(mappedValue == Some(4));
+ mappedValue =
+ mayValue.map([=](const BasicValue& aVal) { return aVal.GetTag() * two; });
+ MOZ_RELEASE_ASSERT(mappedValue == Some(4));
+ mappedValue = mayValueCRef.map(
+ [&](const BasicValue& aVal) { return aVal.GetTag() * two; });
+ MOZ_RELEASE_ASSERT(mappedValue == Some(4));
+
+ // Check that function object qualifiers are preserved when invoked.
+ struct F {
+ std::integral_constant<int, 1> operator()(int) & { return {}; }
+ std::integral_constant<int, 2> operator()(int) const& { return {}; }
+ std::integral_constant<int, 3> operator()(int) && { return {}; }
+ std::integral_constant<int, 4> operator()(int) const&& { return {}; }
+ };
+ Maybe<int> mi = Some(0);
+ const Maybe<int> cmi = Some(0);
+ F f;
+ static_assert(std::is_same<decltype(mi.map(f)),
+ Maybe<std::integral_constant<int, 1>>>::value,
+ "Maybe.map(&)");
+ MOZ_RELEASE_ASSERT(mi.map(f).value()() == 1);
+ static_assert(std::is_same<decltype(cmi.map(f)),
+ Maybe<std::integral_constant<int, 1>>>::value,
+ "const Maybe.map(&)");
+ MOZ_RELEASE_ASSERT(cmi.map(f).value()() == 1);
+ const F cf;
+ static_assert(std::is_same<decltype(mi.map(cf)),
+ Maybe<std::integral_constant<int, 2>>>::value,
+ "Maybe.map(const &)");
+ MOZ_RELEASE_ASSERT(mi.map(cf).value() == 2);
+ static_assert(std::is_same<decltype(cmi.map(cf)),
+ Maybe<std::integral_constant<int, 2>>>::value,
+ "const Maybe.map(const &)");
+ MOZ_RELEASE_ASSERT(cmi.map(cf).value() == 2);
+ static_assert(std::is_same<decltype(mi.map(F{})),
+ Maybe<std::integral_constant<int, 3>>>::value,
+ "Maybe.map(&&)");
+ MOZ_RELEASE_ASSERT(mi.map(F{}).value() == 3);
+ static_assert(std::is_same<decltype(cmi.map(F{})),
+ Maybe<std::integral_constant<int, 3>>>::value,
+ "const Maybe.map(&&)");
+ MOZ_RELEASE_ASSERT(cmi.map(F{}).value() == 3);
+ using CF = const F;
+ static_assert(std::is_same<decltype(mi.map(CF{})),
+ Maybe<std::integral_constant<int, 4>>>::value,
+ "Maybe.map(const &&)");
+ MOZ_RELEASE_ASSERT(mi.map(CF{}).value() == 4);
+ static_assert(std::is_same<decltype(cmi.map(CF{})),
+ Maybe<std::integral_constant<int, 4>>>::value,
+ "const Maybe.map(const &&)");
+ MOZ_RELEASE_ASSERT(cmi.map(CF{}).value() == 4);
+
+ return true;
+}
+
+static bool TestToMaybe() {
+ BasicValue value(1);
+ BasicValue* nullPointer = nullptr;
+
+ // Check that a non-null pointer translates into a Some value.
+ Maybe<BasicValue> mayValue = ToMaybe(&value);
+ static_assert(std::is_same_v<Maybe<BasicValue>, decltype(ToMaybe(&value))>,
+ "ToMaybe should return a Maybe<BasicValue>");
+ MOZ_RELEASE_ASSERT(mayValue.isSome());
+ MOZ_RELEASE_ASSERT(mayValue->GetTag() == 1);
+ MOZ_RELEASE_ASSERT(mayValue->GetStatus() == eWasCopyConstructed);
+ MOZ_RELEASE_ASSERT(value.GetStatus() != eWasMovedFrom);
+
+ // Check that a null pointer translates into a Nothing value.
+ mayValue = ToMaybe(nullPointer);
+ static_assert(
+ std::is_same_v<Maybe<BasicValue>, decltype(ToMaybe(nullPointer))>,
+ "ToMaybe should return a Maybe<BasicValue>");
+ MOZ_RELEASE_ASSERT(mayValue.isNothing());
+
+ return true;
+}
+
+static bool TestComparisonOperators() {
+ Maybe<BasicValue> nothingValue = Nothing();
+ Maybe<BasicValue> anotherNothingValue = Nothing();
+ Maybe<BasicValue> oneValue = Some(BasicValue(1));
+ Maybe<BasicValue> anotherOneValue = Some(BasicValue(1));
+ Maybe<BasicValue> twoValue = Some(BasicValue(2));
+
+ // Check equality.
+ MOZ_RELEASE_ASSERT(nothingValue == anotherNothingValue);
+ MOZ_RELEASE_ASSERT(oneValue == anotherOneValue);
+
+ // Check inequality.
+ MOZ_RELEASE_ASSERT(nothingValue != oneValue);
+ MOZ_RELEASE_ASSERT(oneValue != nothingValue);
+ MOZ_RELEASE_ASSERT(oneValue != twoValue);
+
+ // Check '<'.
+ MOZ_RELEASE_ASSERT(nothingValue < oneValue);
+ MOZ_RELEASE_ASSERT(oneValue < twoValue);
+
+ // Check '<='.
+ MOZ_RELEASE_ASSERT(nothingValue <= anotherNothingValue);
+ MOZ_RELEASE_ASSERT(nothingValue <= oneValue);
+ MOZ_RELEASE_ASSERT(oneValue <= oneValue);
+ MOZ_RELEASE_ASSERT(oneValue <= twoValue);
+
+ // Check '>'.
+ MOZ_RELEASE_ASSERT(oneValue > nothingValue);
+ MOZ_RELEASE_ASSERT(twoValue > oneValue);
+
+ // Check '>='.
+ MOZ_RELEASE_ASSERT(nothingValue >= anotherNothingValue);
+ MOZ_RELEASE_ASSERT(oneValue >= nothingValue);
+ MOZ_RELEASE_ASSERT(oneValue >= oneValue);
+ MOZ_RELEASE_ASSERT(twoValue >= oneValue);
+
+ return true;
+}
+
+// Check that Maybe<> can wrap a superclass that happens to also be a concrete
+// class (i.e. that the compiler doesn't warn when we invoke the superclass's
+// destructor explicitly in |reset()|.
+class MySuperClass {
+ virtual void VirtualMethod() { /* do nothing */
+ }
+};
+
+class MyDerivedClass : public MySuperClass {
+ void VirtualMethod() override { /* do nothing */
+ }
+};
+
+static bool TestVirtualFunction() {
+ Maybe<MySuperClass> super;
+ super.emplace();
+ super.reset();
+
+ Maybe<MyDerivedClass> derived;
+ derived.emplace();
+ derived.reset();
+
+ // If this compiles successfully, we've passed.
+ return true;
+}
+
+static Maybe<int*> ReturnSomeNullptr() { return Some(nullptr); }
+
+struct D {
+ explicit D(const Maybe<int*>&) {}
+};
+
+static bool TestSomeNullptrConversion() {
+ Maybe<int*> m1 = Some(nullptr);
+ MOZ_RELEASE_ASSERT(m1.isSome());
+ MOZ_RELEASE_ASSERT(m1);
+ MOZ_RELEASE_ASSERT(!*m1);
+
+ auto m2 = ReturnSomeNullptr();
+ MOZ_RELEASE_ASSERT(m2.isSome());
+ MOZ_RELEASE_ASSERT(m2);
+ MOZ_RELEASE_ASSERT(!*m2);
+
+ Maybe<decltype(nullptr)> m3 = Some(nullptr);
+ MOZ_RELEASE_ASSERT(m3.isSome());
+ MOZ_RELEASE_ASSERT(m3);
+ MOZ_RELEASE_ASSERT(*m3 == nullptr);
+
+ D d(Some(nullptr));
+
+ return true;
+}
+
+struct Base {};
+struct Derived : Base {};
+
+static Maybe<Base*> ReturnDerivedPointer() {
+ Derived* d = nullptr;
+ return Some(d);
+}
+
+struct ExplicitConstructorBasePointer {
+ explicit ExplicitConstructorBasePointer(const Maybe<Base*>&) {}
+};
+
+static bool TestSomePointerConversion() {
+ Base base;
+ Derived derived;
+
+ Maybe<Base*> m1 = Some(&derived);
+ MOZ_RELEASE_ASSERT(m1.isSome());
+ MOZ_RELEASE_ASSERT(m1);
+ MOZ_RELEASE_ASSERT(*m1 == &derived);
+
+ auto m2 = ReturnDerivedPointer();
+ MOZ_RELEASE_ASSERT(m2.isSome());
+ MOZ_RELEASE_ASSERT(m2);
+ MOZ_RELEASE_ASSERT(*m2 == nullptr);
+
+ Maybe<Base*> m3 = Some(&base);
+ MOZ_RELEASE_ASSERT(m3.isSome());
+ MOZ_RELEASE_ASSERT(m3);
+ MOZ_RELEASE_ASSERT(*m3 == &base);
+
+ auto s1 = Some(&derived);
+ Maybe<Base*> c1(s1);
+ MOZ_RELEASE_ASSERT(c1.isSome());
+ MOZ_RELEASE_ASSERT(c1);
+ MOZ_RELEASE_ASSERT(*c1 == &derived);
+
+ ExplicitConstructorBasePointer ecbp(Some(&derived));
+
+ return true;
+}
+
+struct SourceType1 {
+ int mTag;
+
+ operator int() const { return mTag; }
+};
+struct DestType {
+ int mTag;
+ Status mStatus;
+
+ DestType() : mTag(0), mStatus(eWasDefaultConstructed) {}
+
+ MOZ_IMPLICIT DestType(int aTag) : mTag(aTag), mStatus(eWasConstructed) {}
+
+ MOZ_IMPLICIT DestType(SourceType1&& aSrc)
+ : mTag(aSrc.mTag), mStatus(eWasMoveConstructed) {}
+
+ MOZ_IMPLICIT DestType(const SourceType1& aSrc)
+ : mTag(aSrc.mTag), mStatus(eWasCopyConstructed) {}
+
+ DestType& operator=(int aTag) {
+ mTag = aTag;
+ mStatus = eWasAssigned;
+ return *this;
+ }
+
+ DestType& operator=(SourceType1&& aSrc) {
+ mTag = aSrc.mTag;
+ mStatus = eWasMoveAssigned;
+ return *this;
+ }
+
+ DestType& operator=(const SourceType1& aSrc) {
+ mTag = aSrc.mTag;
+ mStatus = eWasCopyAssigned;
+ return *this;
+ }
+};
+struct SourceType2 {
+ int mTag;
+
+ operator DestType() const& {
+ DestType result;
+ result.mTag = mTag;
+ result.mStatus = eWasCopiedFrom;
+ return result;
+ }
+
+ operator DestType() && {
+ DestType result;
+ result.mTag = mTag;
+ result.mStatus = eWasMovedFrom;
+ return result;
+ }
+};
+
+static bool TestTypeConversion() {
+ {
+ Maybe<SourceType1> src = Some(SourceType1{1});
+ Maybe<DestType> dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasCopyConstructed);
+
+ src = Some(SourceType1{2});
+ dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasCopyAssigned);
+ }
+
+ {
+ Maybe<SourceType1> src = Some(SourceType1{1});
+ Maybe<DestType> dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasMoveConstructed);
+
+ src = Some(SourceType1{2});
+ dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasMoveAssigned);
+ }
+
+ {
+ Maybe<SourceType2> src = Some(SourceType2{1});
+ Maybe<DestType> dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasCopiedFrom);
+
+ src = Some(SourceType2{2});
+ dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasCopiedFrom);
+ }
+
+ {
+ Maybe<SourceType2> src = Some(SourceType2{1});
+ Maybe<DestType> dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasMovedFrom);
+
+ src = Some(SourceType2{2});
+ dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasMovedFrom);
+ }
+
+ {
+ Maybe<int> src = Some(1);
+ Maybe<DestType> dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && *src == 1);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasConstructed);
+
+ src = Some(2);
+ dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && *src == 2);
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasAssigned);
+ }
+
+ {
+ Maybe<int> src = Some(1);
+ Maybe<DestType> dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasConstructed);
+
+ src = Some(2);
+ dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && dest->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest->mStatus == eWasAssigned);
+ }
+
+ {
+ Maybe<SourceType1> src = Some(SourceType1{1});
+ Maybe<int> dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 1);
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 1);
+
+ src = Some(SourceType1{2});
+ dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && src->mTag == 2);
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 2);
+ }
+
+ {
+ Maybe<SourceType1> src = Some(SourceType1{1});
+ Maybe<int> dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 1);
+
+ src = Some(SourceType1{2});
+ dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 2);
+ }
+
+ {
+ Maybe<size_t> src = Some(1);
+ Maybe<char16_t> dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && *src == 1);
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 1);
+
+ src = Some(2);
+ dest = src;
+ MOZ_RELEASE_ASSERT(src.isSome() && *src == 2);
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 2);
+ }
+
+ {
+ Maybe<size_t> src = Some(1);
+ Maybe<char16_t> dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 1);
+
+ src = Some(2);
+ dest = std::move(src);
+ MOZ_RELEASE_ASSERT(src.isNothing());
+ MOZ_RELEASE_ASSERT(dest.isSome() && *dest == 2);
+ }
+
+ return true;
+}
+
+static bool TestReference() {
+ static_assert(std::is_trivially_destructible_v<Maybe<int&>>);
+ static_assert(std::is_trivially_copy_constructible_v<Maybe<int&>>);
+ static_assert(std::is_trivially_copy_assignable_v<Maybe<int&>>);
+
+ static_assert(Maybe<int&>{}.isNothing());
+ static_assert(Maybe<int&>{Nothing{}}.isNothing());
+
+ {
+ Maybe<int&> defaultConstructed;
+
+ MOZ_RELEASE_ASSERT(defaultConstructed.isNothing());
+ MOZ_RELEASE_ASSERT(!defaultConstructed.isSome());
+ MOZ_RELEASE_ASSERT(!defaultConstructed);
+ }
+
+ {
+ Maybe<int&> nothing = Nothing();
+
+ MOZ_RELEASE_ASSERT(nothing.isNothing());
+ MOZ_RELEASE_ASSERT(!nothing.isSome());
+ MOZ_RELEASE_ASSERT(!nothing);
+ }
+
+ {
+ int foo = 42, bar = 42;
+ Maybe<int&> some = SomeRef(foo);
+
+ MOZ_RELEASE_ASSERT(!some.isNothing());
+ MOZ_RELEASE_ASSERT(some.isSome());
+ MOZ_RELEASE_ASSERT(some);
+ MOZ_RELEASE_ASSERT(&some.ref() == &foo);
+
+ MOZ_RELEASE_ASSERT(some.refEquals(foo));
+ MOZ_RELEASE_ASSERT(some.refEquals(SomeRef(foo)));
+ MOZ_RELEASE_ASSERT(!some.refEquals(Nothing()));
+ MOZ_RELEASE_ASSERT(!some.refEquals(bar));
+ MOZ_RELEASE_ASSERT(!some.refEquals(SomeRef(bar)));
+
+ some.ref()++;
+ MOZ_RELEASE_ASSERT(43 == foo);
+
+ (*some)++;
+ MOZ_RELEASE_ASSERT(44 == foo);
+ }
+
+ {
+ int foo = 42, bar = 42;
+ Maybe<int&> some;
+ some.emplace(foo);
+
+ MOZ_RELEASE_ASSERT(!some.isNothing());
+ MOZ_RELEASE_ASSERT(some.isSome());
+ MOZ_RELEASE_ASSERT(some);
+ MOZ_RELEASE_ASSERT(&some.ref() == &foo);
+
+ MOZ_RELEASE_ASSERT(some.refEquals(foo));
+ MOZ_RELEASE_ASSERT(some.refEquals(SomeRef(foo)));
+ MOZ_RELEASE_ASSERT(!some.refEquals(Nothing()));
+ MOZ_RELEASE_ASSERT(!some.refEquals(bar));
+ MOZ_RELEASE_ASSERT(!some.refEquals(SomeRef(bar)));
+
+ some.ref()++;
+ MOZ_RELEASE_ASSERT(43 == foo);
+ }
+
+ {
+ Maybe<int&> defaultConstructed;
+ defaultConstructed.reset();
+
+ MOZ_RELEASE_ASSERT(defaultConstructed.isNothing());
+ MOZ_RELEASE_ASSERT(!defaultConstructed.isSome());
+ MOZ_RELEASE_ASSERT(!defaultConstructed);
+ }
+
+ {
+ int foo = 42;
+ Maybe<int&> some = SomeRef(foo);
+ some.reset();
+
+ MOZ_RELEASE_ASSERT(some.isNothing());
+ MOZ_RELEASE_ASSERT(!some.isSome());
+ MOZ_RELEASE_ASSERT(!some);
+ }
+
+ {
+ int foo = 42;
+ Maybe<int&> some = SomeRef(foo);
+
+ auto& applied = some.apply([](int& ref) { ref++; });
+
+ MOZ_RELEASE_ASSERT(&some == &applied);
+ MOZ_RELEASE_ASSERT(43 == foo);
+ }
+
+ {
+ Maybe<int&> nothing;
+
+ auto& applied = nothing.apply([](int& ref) { ref++; });
+
+ MOZ_RELEASE_ASSERT(&nothing == &applied);
+ }
+
+ {
+ int foo = 42;
+ Maybe<int&> some = SomeRef(foo);
+
+ auto mapped = some.map([](int& ref) { return &ref; });
+ static_assert(std::is_same_v<decltype(mapped), Maybe<int*>>);
+
+ MOZ_RELEASE_ASSERT(&foo == *mapped);
+ }
+
+ {
+ Maybe<int&> nothing;
+
+ auto mapped = nothing.map([](int& ref) { return &ref; });
+
+ MOZ_RELEASE_ASSERT(mapped.isNothing());
+ MOZ_RELEASE_ASSERT(!mapped.isSome());
+ MOZ_RELEASE_ASSERT(!mapped);
+ }
+
+ {
+ int foo = 42;
+ auto someRef = ToMaybeRef(&foo);
+
+ static_assert(std::is_same_v<decltype(someRef), Maybe<int&>>);
+
+ MOZ_RELEASE_ASSERT(someRef.isSome());
+ MOZ_RELEASE_ASSERT(&foo == &someRef.ref());
+ }
+
+ {
+ int* fooPtr = nullptr;
+ auto someRef = ToMaybeRef(fooPtr);
+
+ static_assert(std::is_same_v<decltype(someRef), Maybe<int&>>);
+
+ MOZ_RELEASE_ASSERT(someRef.isNothing());
+ }
+
+ return true;
+}
+
+// These are quasi-implementation details, but we assert them here to prevent
+// backsliding to earlier times when Maybe<T> for smaller T took up more space
+// than T's alignment required.
+
+static_assert(sizeof(Maybe<char>) == 2 * sizeof(char),
+ "Maybe<char> shouldn't bloat at all ");
+static_assert(sizeof(Maybe<bool>) <= 2 * sizeof(bool),
+ "Maybe<bool> shouldn't bloat");
+static_assert(sizeof(Maybe<int>) <= 2 * sizeof(int),
+ "Maybe<int> shouldn't bloat");
+static_assert(sizeof(Maybe<long>) <= 2 * sizeof(long),
+ "Maybe<long> shouldn't bloat");
+static_assert(sizeof(Maybe<double>) <= 2 * sizeof(double),
+ "Maybe<double> shouldn't bloat");
+static_assert(sizeof(Maybe<int&>) == sizeof(int*));
+
+int main() {
+ RUN_TEST(TestBasicFeatures);
+ RUN_TEST(TestCopyAndMove);
+ RUN_TEST(TestFunctionalAccessors);
+ RUN_TEST(TestApply);
+ RUN_TEST(TestMap);
+ RUN_TEST(TestToMaybe);
+ RUN_TEST(TestComparisonOperators);
+ RUN_TEST(TestVirtualFunction);
+ RUN_TEST(TestSomeNullptrConversion);
+ RUN_TEST(TestSomePointerConversion);
+ RUN_TEST(TestTypeConversion);
+ RUN_TEST(TestReference);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 14:43:40 +0000