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fune/mfbt/tests/TestMaybe.cpp
Emilio Cobos Álvarez fffb25b74f Bug 1465585: Switch from mozilla::Move to std::move. r=froydnj 
This was done automatically replacing:

  s/mozilla::Move/std::move/
  s/ Move(/ std::move(/
  s/(Move(/(std::move(/

Removing the 'using mozilla::Move;' lines.

And then with a few manual fixups, see the bug for the split series..

MozReview-Commit-ID: Jxze3adipUh
2018-06-01 10:45:27 +02:00

1099 lines
33 KiB
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/* -*- 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/TemplateLib.h"
#include "mozilla/Types.h"
#include "mozilla/TypeTraits.h"
#include "mozilla/UniquePtr.h"
using mozilla::IsSame;
using mozilla::Maybe;
using mozilla::Nothing;
using mozilla::Some;
using mozilla::Swap;
using mozilla::ToMaybe;
using mozilla::UniquePtr;
#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,
eWasAssigned,
eWasCopyAssigned,
eWasMoveAssigned,
eWasCopiedFrom,
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();
// 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));
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 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);
// 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(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;
}
// 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");
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);
return 0;
}
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