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Diffstat (limited to 'mfbt/tests/TestMaybe.cpp')
| -rw-r--r-- | mfbt/tests/TestMaybe.cpp | 860 |
1 files changed, 860 insertions, 0 deletions
diff --git a/mfbt/tests/TestMaybe.cpp b/mfbt/tests/TestMaybe.cpp new file mode 100644 index 000000000..5817ab428 --- /dev/null +++ b/mfbt/tests/TestMaybe.cpp @@ -0,0 +1,860 @@ +/* -*- 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 <utility> + +#include "mozilla/Assertions.h" +#include "mozilla/Attributes.h" +#include "mozilla/Compiler.h" +#include "mozilla/Maybe.h" +#include "mozilla/Move.h" +#include "mozilla/Types.h" +#include "mozilla/TypeTraits.h" +#include "mozilla/UniquePtr.h" + +using mozilla::IsSame; +using mozilla::Maybe; +using mozilla::Move; +using mozilla::Nothing; +using mozilla::Some; +using mozilla::Swap; +using mozilla::ToMaybe; +using mozilla::UniquePtr; + +#if MOZ_IS_MSVC + template<typename T> struct Identity { typedef T type; }; +# define DECLTYPE(EXPR) Identity<decltype(EXPR)>::type +#else +# define DECLTYPE(EXPR) decltype(EXPR) +#endif + +#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, + eWasCopyAssigned, + eWasMoveAssigned, + eWasMovedFrom +}; + +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() { --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: + 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; } + +private: + UnmovableValue(UnmovableValue&& aOther) = delete; + UnmovableValue& operator=(UnmovableValue&& aOther) = delete; + + Status mStatus; +}; + +struct UncopyableUnmovableValue +{ + UncopyableUnmovableValue() + : mStatus(eWasDefaultConstructed) + { + ++sUndestroyedObjects; + } + + explicit UncopyableUnmovableValue(int) + : mStatus(eWasConstructed) + { + ++sUndestroyedObjects; + } + + ~UncopyableUnmovableValue() { --sUndestroyedObjects; } + + Status GetStatus() { 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 bool +TestBasicFeatures() +{ + // Check that a Maybe<T> is initialized to Nothing. + Maybe<BasicValue> mayValue; + static_assert(IsSame<BasicValue, DECLTYPE(mayValue)::ValueType>::value, + "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()); + MOZ_RELEASE_ASSERT(mayValue.value() == BasicValue()); + static_assert(IsSame<BasicValue, DECLTYPE(mayValue.value())>::value, + "value() should return a BasicValue"); + MOZ_RELEASE_ASSERT(mayValue.ref() == BasicValue()); + static_assert(IsSame<BasicValue&, DECLTYPE(mayValue.ref())>::value, + "ref() should return a BasicValue&"); + MOZ_RELEASE_ASSERT(mayValue.ptr() != nullptr); + static_assert(IsSame<BasicValue*, DECLTYPE(mayValue.ptr())>::value, + "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 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()); + MOZ_RELEASE_ASSERT(mayValueCRef.value() == BasicValue()); + static_assert(IsSame<BasicValue, DECLTYPE(mayValueCRef.value())>::value, + "value() should return a BasicValue"); + MOZ_RELEASE_ASSERT(mayValueCRef.ref() == BasicValue()); + static_assert(IsSame<const BasicValue&, + DECLTYPE(mayValueCRef.ref())>::value, + "ref() should return a const BasicValue&"); + MOZ_RELEASE_ASSERT(mayValueCRef.ptr() != nullptr); + static_assert(IsSame<const BasicValue*, + DECLTYPE(mayValueCRef.ptr())>::value, + "ptr() should return a const BasicValue*"); + MOZ_RELEASE_ASSERT(mayValueCRef->GetStatus() == eWasDefaultConstructed); + mayValue.reset(); + + return true; +} + +static bool +TestCopyAndMove() +{ + // 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(mayBasicValue->GetStatus() == eWasMoveConstructed); + MOZ_RELEASE_ASSERT(mayBasicValue->GetTag() == 1); + mayBasicValue = Some(BasicValue(2)); + MOZ_RELEASE_ASSERT(mayBasicValue->GetStatus() == eWasMoveAssigned); + MOZ_RELEASE_ASSERT(mayBasicValue->GetTag() == 2); + mayBasicValue.reset(); + mayBasicValue.emplace(BasicValue(3)); + 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 Move() works. (Another sanity check for move support.) + Maybe<BasicValue> mayBasicValue3 = Some(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(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(Move(*mayBasicValue3)); + MOZ_RELEASE_ASSERT(mayBasicValue4->GetStatus() == eWasMoveConstructed); + MOZ_RELEASE_ASSERT(mayBasicValue4->GetTag() == 6); + MOZ_RELEASE_ASSERT(mayBasicValue3->GetStatus() == eWasMovedFrom); + + // Check that we always get copies for types that don't support moves. + // XXX(seth): These tests fail but probably shouldn't. For now we'll just + // consider using Maybe with types that allow copies but have deleted or + // private move constructors, or which do not support copy assignment, to + // be supported only to the extent that we need for existing code to work. + // These tests should work again when we fix bug 1052940. + /* + 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); + */ + + // 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); + + // Check that types that support neither moves or copies work. + Maybe<UncopyableUnmovableValue> mayUncopyableUnmovableValue; + mayUncopyableUnmovableValue.emplace(); + MOZ_RELEASE_ASSERT(mayUncopyableUnmovableValue->GetStatus() == eWasDefaultConstructed); + mayUncopyableUnmovableValue.reset(); + mayUncopyableUnmovableValue.emplace(0); + MOZ_RELEASE_ASSERT(mayUncopyableUnmovableValue->GetStatus() == eWasConstructed); + + 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(IsSame<BasicValue, + DECLTYPE(someValue.valueOr(value))>::value, + "valueOr should return a BasicValue"); + MOZ_RELEASE_ASSERT(someValue.valueOrFrom(&MakeBasicValue) == BasicValue(3)); + static_assert(IsSame<BasicValue, + DECLTYPE(someValue.valueOrFrom(&MakeBasicValue))>::value, + "valueOrFrom should return a BasicValue"); + MOZ_RELEASE_ASSERT(someValue.ptrOr(&value) != &value); + static_assert(IsSame<BasicValue*, + DECLTYPE(someValue.ptrOr(&value))>::value, + "ptrOr should return a BasicValue*"); + MOZ_RELEASE_ASSERT(*someValue.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(3)); + static_assert(IsSame<BasicValue*, + DECLTYPE(someValue.ptrOrFrom(&MakeBasicValuePtr))>::value, + "ptrOrFrom should return a BasicValue*"); + MOZ_RELEASE_ASSERT(someValue.refOr(value) == BasicValue(3)); + static_assert(IsSame<BasicValue&, + DECLTYPE(someValue.refOr(value))>::value, + "refOr should return a BasicValue&"); + MOZ_RELEASE_ASSERT(someValue.refOrFrom(&MakeBasicValueRef) == BasicValue(3)); + static_assert(IsSame<BasicValue&, + DECLTYPE(someValue.refOrFrom(&MakeBasicValueRef))>::value, + "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(IsSame<BasicValue, + DECLTYPE(someValueCRef.valueOr(value))>::value, + "valueOr should return a BasicValue"); + MOZ_RELEASE_ASSERT(someValueCRef.valueOrFrom(&MakeBasicValue) == BasicValue(3)); + static_assert(IsSame<BasicValue, + DECLTYPE(someValueCRef.valueOrFrom(&MakeBasicValue))>::value, + "valueOrFrom should return a BasicValue"); + MOZ_RELEASE_ASSERT(someValueCRef.ptrOr(&value) != &value); + static_assert(IsSame<const BasicValue*, + DECLTYPE(someValueCRef.ptrOr(&value))>::value, + "ptrOr should return a const BasicValue*"); + MOZ_RELEASE_ASSERT(*someValueCRef.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(3)); + static_assert(IsSame<const BasicValue*, + DECLTYPE(someValueCRef.ptrOrFrom(&MakeBasicValuePtr))>::value, + "ptrOrFrom should return a const BasicValue*"); + MOZ_RELEASE_ASSERT(someValueCRef.refOr(value) == BasicValue(3)); + static_assert(IsSame<const BasicValue&, + DECLTYPE(someValueCRef.refOr(value))>::value, + "refOr should return a const BasicValue&"); + MOZ_RELEASE_ASSERT(someValueCRef.refOrFrom(&MakeBasicValueRef) == BasicValue(3)); + static_assert(IsSame<const BasicValue&, + DECLTYPE(someValueCRef.refOrFrom(&MakeBasicValueRef))>::value, + "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(IsSame<BasicValue, + DECLTYPE(noneValue.valueOr(value))>::value, + "valueOr should return a BasicValue"); + MOZ_RELEASE_ASSERT(noneValue.valueOrFrom(&MakeBasicValue) == BasicValue(9)); + static_assert(IsSame<BasicValue, + DECLTYPE(noneValue.valueOrFrom(&MakeBasicValue))>::value, + "valueOrFrom should return a BasicValue"); + MOZ_RELEASE_ASSERT(noneValue.ptrOr(&value) == &value); + static_assert(IsSame<BasicValue*, + DECLTYPE(noneValue.ptrOr(&value))>::value, + "ptrOr should return a BasicValue*"); + MOZ_RELEASE_ASSERT(*noneValue.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(9)); + static_assert(IsSame<BasicValue*, + DECLTYPE(noneValue.ptrOrFrom(&MakeBasicValuePtr))>::value, + "ptrOrFrom should return a BasicValue*"); + MOZ_RELEASE_ASSERT(noneValue.refOr(value) == BasicValue(9)); + static_assert(IsSame<BasicValue&, + DECLTYPE(noneValue.refOr(value))>::value, + "refOr should return a BasicValue&"); + MOZ_RELEASE_ASSERT(noneValue.refOrFrom(&MakeBasicValueRef) == BasicValue(9)); + static_assert(IsSame<BasicValue&, + DECLTYPE(noneValue.refOrFrom(&MakeBasicValueRef))>::value, + "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(IsSame<BasicValue, + DECLTYPE(noneValueCRef.valueOr(value))>::value, + "valueOr should return a BasicValue"); + MOZ_RELEASE_ASSERT(noneValueCRef.valueOrFrom(&MakeBasicValue) == BasicValue(9)); + static_assert(IsSame<BasicValue, + DECLTYPE(noneValueCRef.valueOrFrom(&MakeBasicValue))>::value, + "valueOrFrom should return a BasicValue"); + MOZ_RELEASE_ASSERT(noneValueCRef.ptrOr(&value) == &value); + static_assert(IsSame<const BasicValue*, + DECLTYPE(noneValueCRef.ptrOr(&value))>::value, + "ptrOr should return a const BasicValue*"); + MOZ_RELEASE_ASSERT(*noneValueCRef.ptrOrFrom(&MakeBasicValuePtr) == BasicValue(9)); + static_assert(IsSame<const BasicValue*, + DECLTYPE(noneValueCRef.ptrOrFrom(&MakeBasicValuePtr))>::value, + "ptrOrFrom should return a const BasicValue*"); + MOZ_RELEASE_ASSERT(noneValueCRef.refOr(value) == BasicValue(9)); + static_assert(IsSame<const BasicValue&, + DECLTYPE(noneValueCRef.refOr(value))>::value, + "refOr should return a const BasicValue&"); + MOZ_RELEASE_ASSERT(noneValueCRef.refOrFrom(&MakeBasicValueRef) == BasicValue(9)); + static_assert(IsSame<const BasicValue&, + DECLTYPE(noneValueCRef.refOrFrom(&MakeBasicValueRef))>::value, + "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(IsSame<Maybe<int>, + DECLTYPE(mayValue.map(&TimesTwo))>::value, + "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(IsSame<Maybe<int>, + DECLTYPE(mayValueCRef.map(&TimesTwo))>::value, + "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)); + + 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(IsSame<Maybe<BasicValue>, DECLTYPE(ToMaybe(&value))>::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(IsSame<Maybe<BasicValue>, DECLTYPE(ToMaybe(nullPointer))>::value, + "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(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(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; +} + +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); + + return 0; +} |