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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
/* A type/length-parametrized vector class. */
#ifndef mozilla_Vector_h
#define mozilla_Vector_h
#include <new> // for placement new
#include <utility>
#include "mozilla/Alignment.h"
#include "mozilla/AllocPolicy.h"
#include "mozilla/ArrayUtils.h" // for PointerRangeSize
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/OperatorNewExtensions.h"
#include "mozilla/ReentrancyGuard.h"
#include "mozilla/Span.h"
#include "mozilla/TemplateLib.h"
#include "mozilla/TypeTraits.h"
namespace mozilla {
template <typename T, size_t N, class AllocPolicy>
class Vector;
namespace detail {
/*
* Check that the given capacity wastes the minimal amount of space if
* allocated on the heap. This means that aCapacity*sizeof(T) is as close to a
* power-of-two as possible. growStorageBy() is responsible for ensuring this.
*/
template <typename T>
static bool CapacityHasExcessSpace(size_t aCapacity) {
size_t size = aCapacity * sizeof(T);
return RoundUpPow2(size) - size >= sizeof(T);
}
/*
* This template class provides a default implementation for vector operations
* when the element type is not known to be a POD, as judged by IsPod.
*/
template <typename T, size_t N, class AP, bool IsPod>
struct VectorImpl {
/*
* Constructs an object in the uninitialized memory at *aDst with aArgs.
*/
template <typename... Args>
MOZ_NONNULL(1)
static inline void new_(T* aDst, Args&&... aArgs) {
new (KnownNotNull, aDst) T(std::forward<Args>(aArgs)...);
}
/* Destroys constructed objects in the range [aBegin, aEnd). */
static inline void destroy(T* aBegin, T* aEnd) {
MOZ_ASSERT(aBegin <= aEnd);
for (T* p = aBegin; p < aEnd; ++p) {
p->~T();
}
}
/* Constructs objects in the uninitialized range [aBegin, aEnd). */
static inline void initialize(T* aBegin, T* aEnd) {
MOZ_ASSERT(aBegin <= aEnd);
for (T* p = aBegin; p < aEnd; ++p) {
new_(p);
}
}
/*
* Copy-constructs objects in the uninitialized range
* [aDst, aDst+(aSrcEnd-aSrcStart)) from the range [aSrcStart, aSrcEnd).
*/
template <typename U>
static inline void copyConstruct(T* aDst, const U* aSrcStart,
const U* aSrcEnd) {
MOZ_ASSERT(aSrcStart <= aSrcEnd);
for (const U* p = aSrcStart; p < aSrcEnd; ++p, ++aDst) {
new_(aDst, *p);
}
}
/*
* Move-constructs objects in the uninitialized range
* [aDst, aDst+(aSrcEnd-aSrcStart)) from the range [aSrcStart, aSrcEnd).
*/
template <typename U>
static inline void moveConstruct(T* aDst, U* aSrcStart, U* aSrcEnd) {
MOZ_ASSERT(aSrcStart <= aSrcEnd);
for (U* p = aSrcStart; p < aSrcEnd; ++p, ++aDst) {
new_(aDst, std::move(*p));
}
}
/*
* Copy-constructs objects in the uninitialized range [aDst, aDst+aN) from
* the same object aU.
*/
template <typename U>
static inline void copyConstructN(T* aDst, size_t aN, const U& aU) {
for (T* end = aDst + aN; aDst < end; ++aDst) {
new_(aDst, aU);
}
}
/*
* Grows the given buffer to have capacity aNewCap, preserving the objects
* constructed in the range [begin, end) and updating aV. Assumes that (1)
* aNewCap has not overflowed, and (2) multiplying aNewCap by sizeof(T) will
* not overflow.
*/
static inline MOZ_MUST_USE bool growTo(Vector<T, N, AP>& aV, size_t aNewCap) {
MOZ_ASSERT(!aV.usingInlineStorage());
MOZ_ASSERT(!CapacityHasExcessSpace<T>(aNewCap));
T* newbuf = aV.template pod_malloc<T>(aNewCap);
if (MOZ_UNLIKELY(!newbuf)) {
return false;
}
T* dst = newbuf;
T* src = aV.beginNoCheck();
for (; src < aV.endNoCheck(); ++dst, ++src) {
new_(dst, std::move(*src));
}
VectorImpl::destroy(aV.beginNoCheck(), aV.endNoCheck());
aV.free_(aV.mBegin, aV.mTail.mCapacity);
aV.mBegin = newbuf;
/* aV.mLength is unchanged. */
aV.mTail.mCapacity = aNewCap;
return true;
}
};
/*
* This partial template specialization provides a default implementation for
* vector operations when the element type is known to be a POD, as judged by
* IsPod.
*/
template <typename T, size_t N, class AP>
struct VectorImpl<T, N, AP, true> {
template <typename... Args>
MOZ_NONNULL(1)
static inline void new_(T* aDst, Args&&... aArgs) {
// Explicitly construct a local object instead of using a temporary since
// T(args...) will be treated like a C-style cast in the unary case and
// allow unsafe conversions. Both forms should be equivalent to an
// optimizing compiler.
T temp(std::forward<Args>(aArgs)...);
*aDst = temp;
}
static inline void destroy(T*, T*) {}
static inline void initialize(T* aBegin, T* aEnd) {
/*
* You would think that memset would be a big win (or even break even)
* when we know T is a POD. But currently it's not. This is probably
* because |append| tends to be given small ranges and memset requires
* a function call that doesn't get inlined.
*
* memset(aBegin, 0, sizeof(T) * (aEnd - aBegin));
*/
MOZ_ASSERT(aBegin <= aEnd);
for (T* p = aBegin; p < aEnd; ++p) {
new_(p);
}
}
template <typename U>
static inline void copyConstruct(T* aDst, const U* aSrcStart,
const U* aSrcEnd) {
/*
* See above memset comment. Also, notice that copyConstruct is
* currently templated (T != U), so memcpy won't work without
* requiring T == U.
*
* memcpy(aDst, aSrcStart, sizeof(T) * (aSrcEnd - aSrcStart));
*/
MOZ_ASSERT(aSrcStart <= aSrcEnd);
for (const U* p = aSrcStart; p < aSrcEnd; ++p, ++aDst) {
new_(aDst, *p);
}
}
template <typename U>
static inline void moveConstruct(T* aDst, const U* aSrcStart,
const U* aSrcEnd) {
copyConstruct(aDst, aSrcStart, aSrcEnd);
}
static inline void copyConstructN(T* aDst, size_t aN, const T& aT) {
for (T* end = aDst + aN; aDst < end; ++aDst) {
new_(aDst, aT);
}
}
static inline MOZ_MUST_USE bool growTo(Vector<T, N, AP>& aV, size_t aNewCap) {
MOZ_ASSERT(!aV.usingInlineStorage());
MOZ_ASSERT(!CapacityHasExcessSpace<T>(aNewCap));
T* newbuf =
aV.template pod_realloc<T>(aV.mBegin, aV.mTail.mCapacity, aNewCap);
if (MOZ_UNLIKELY(!newbuf)) {
return false;
}
aV.mBegin = newbuf;
/* aV.mLength is unchanged. */
aV.mTail.mCapacity = aNewCap;
return true;
}
};
// A struct for TestVector.cpp to access private internal fields.
// DO NOT DEFINE IN YOUR OWN CODE.
struct VectorTesting;
} // namespace detail
/*
* STL-like container providing a short-lived, dynamic buffer. Vector calls the
* constructors/destructors of all elements stored in its internal buffer, so
* non-PODs may be safely used. Additionally, Vector will store the first N
* elements in-place before resorting to dynamic allocation.
*
* T requirements:
* - default and copy constructible, assignable, destructible
* - operations do not throw
* MinInlineCapacity requirements:
* - any value, however, MinInlineCapacity is clamped to min/max values
* AllocPolicy:
* - see "Allocation policies" in AllocPolicy.h (defaults to
* mozilla::MallocAllocPolicy)
*
* Vector is not reentrant: T member functions called during Vector member
* functions must not call back into the same object!
*/
template <typename T, size_t MinInlineCapacity = 0,
class AllocPolicy = MallocAllocPolicy>
class MOZ_NON_PARAM Vector final : private AllocPolicy {
/* utilities */
static constexpr bool kElemIsPod = IsPod<T>::value;
typedef detail::VectorImpl<T, MinInlineCapacity, AllocPolicy, kElemIsPod>
Impl;
friend struct detail::VectorImpl<T, MinInlineCapacity, AllocPolicy,
kElemIsPod>;
friend struct detail::VectorTesting;
MOZ_MUST_USE bool growStorageBy(size_t aIncr);
MOZ_MUST_USE bool convertToHeapStorage(size_t aNewCap);
MOZ_MUST_USE bool maybeCheckSimulatedOOM(size_t aRequestedSize);
/* magic constants */
/**
* The maximum space allocated for inline element storage.
*
* We reduce space by what the AllocPolicy base class and prior Vector member
* fields likely consume to attempt to play well with binary size classes.
*/
static constexpr size_t kMaxInlineBytes =
1024 -
(sizeof(AllocPolicy) + sizeof(T*) + sizeof(size_t) + sizeof(size_t));
/**
* The number of T elements of inline capacity built into this Vector. This
* is usually |MinInlineCapacity|, but it may be less (or zero!) for large T.
*
* We use a partially-specialized template (not explicit specialization, which
* is only allowed at namespace scope) to compute this value. The benefit is
* that |sizeof(T)| need not be computed, and |T| doesn't have to be fully
* defined at the time |Vector<T>| appears, if no inline storage is requested.
*/
template <size_t MinimumInlineCapacity, size_t Dummy>
struct ComputeCapacity {
static constexpr size_t value =
tl::Min<MinimumInlineCapacity, kMaxInlineBytes / sizeof(T)>::value;
};
template <size_t Dummy>
struct ComputeCapacity<0, Dummy> {
static constexpr size_t value = 0;
};
/** The actual inline capacity in number of elements T. This may be zero! */
static constexpr size_t kInlineCapacity =
ComputeCapacity<MinInlineCapacity, 0>::value;
/* member data */
/*
* Pointer to the buffer, be it inline or heap-allocated. Only [mBegin,
* mBegin + mLength) hold valid constructed T objects. The range [mBegin +
* mLength, mBegin + mCapacity) holds uninitialized memory. The range
* [mBegin + mLength, mBegin + mReserved) also holds uninitialized memory
* previously allocated by a call to reserve().
*/
T* mBegin;
/* Number of elements in the vector. */
size_t mLength;
/*
* Memory used to store capacity, reserved element count (debug builds only),
* and inline storage. The simple "answer" is:
*
* size_t mCapacity;
* #ifdef DEBUG
* size_t mReserved;
* #endif
* alignas(T) unsigned char mBytes[kInlineCapacity * sizeof(T)];
*
* but there are complications. First, C++ forbids zero-sized arrays that
* might result. Second, we don't want zero capacity to affect Vector's size
* (even empty classes take up a byte, unless they're base classes).
*
* Yet again, we eliminate the zero-sized array using partial specialization.
* And we eliminate potential size hit by putting capacity/reserved in one
* struct, then putting the array (if any) in a derived struct. If no array
* is needed, the derived struct won't consume extra space.
*/
struct CapacityAndReserved {
explicit CapacityAndReserved(size_t aCapacity, size_t aReserved)
: mCapacity(aCapacity)
#ifdef DEBUG
,
mReserved(aReserved)
#endif
{
}
CapacityAndReserved() = default;
/* Max number of elements storable in the vector without resizing. */
size_t mCapacity;
#ifdef DEBUG
/* Max elements of reserved or used space in this vector. */
size_t mReserved;
#endif
};
// Silence warnings about this struct possibly being padded dued to the
// alignas() in it -- there's nothing we can do to avoid it.
#ifdef _MSC_VER
# pragma warning(push)
# pragma warning(disable : 4324)
#endif // _MSC_VER
template <size_t Capacity, size_t Dummy>
struct CRAndStorage : CapacityAndReserved {
explicit CRAndStorage(size_t aCapacity, size_t aReserved)
: CapacityAndReserved(aCapacity, aReserved) {}
CRAndStorage() = default;
alignas(T) unsigned char mBytes[Capacity * sizeof(T)];
// GCC fails due to -Werror=strict-aliasing if |mBytes| is directly cast to
// T*. Indirecting through this function addresses the problem.
void* data() { return mBytes; }
T* storage() { return static_cast<T*>(data()); }
};
template <size_t Dummy>
struct CRAndStorage<0, Dummy> : CapacityAndReserved {
explicit CRAndStorage(size_t aCapacity, size_t aReserved)
: CapacityAndReserved(aCapacity, aReserved) {}
CRAndStorage() = default;
T* storage() {
// If this returns |nullptr|, functions like |Vector::begin()| would too,
// breaking callers that pass a vector's elements as pointer/length to
// code that bounds its operation by length but (even just as a sanity
// check) always wants a non-null pointer. Fake up an aligned, non-null
// pointer to support these callers.
return reinterpret_cast<T*>(sizeof(T));
}
};
CRAndStorage<kInlineCapacity, 0> mTail;
#ifdef _MSC_VER
# pragma warning(pop)
#endif // _MSC_VER
#ifdef DEBUG
friend class ReentrancyGuard;
bool mEntered;
#endif
/* private accessors */
bool usingInlineStorage() const {
return mBegin == const_cast<Vector*>(this)->inlineStorage();
}
T* inlineStorage() { return mTail.storage(); }
T* beginNoCheck() const { return mBegin; }
T* endNoCheck() { return mBegin + mLength; }
const T* endNoCheck() const { return mBegin + mLength; }
#ifdef DEBUG
/**
* The amount of explicitly allocated space in this vector that is immediately
* available to be filled by appending additional elements. This value is
* always greater than or equal to |length()| -- the vector's actual elements
* are implicitly reserved. This value is always less than or equal to
* |capacity()|. It may be explicitly increased using the |reserve()| method.
*/
size_t reserved() const {
MOZ_ASSERT(mLength <= mTail.mReserved);
MOZ_ASSERT(mTail.mReserved <= mTail.mCapacity);
return mTail.mReserved;
}
#endif
/* Append operations guaranteed to succeed due to pre-reserved space. */
template <typename U>
void internalAppend(U&& aU);
template <typename U, size_t O, class BP>
void internalAppendAll(const Vector<U, O, BP>& aU);
void internalAppendN(const T& aT, size_t aN);
template <typename U>
void internalAppend(const U* aBegin, size_t aLength);
public:
static const size_t sMaxInlineStorage = MinInlineCapacity;
typedef T ElementType;
explicit Vector(AllocPolicy = AllocPolicy());
Vector(Vector&&); /* Move constructor. */
Vector& operator=(Vector&&); /* Move assignment. */
~Vector();
/* accessors */
const AllocPolicy& allocPolicy() const { return *this; }
AllocPolicy& allocPolicy() { return *this; }
enum { InlineLength = MinInlineCapacity };
size_t length() const { return mLength; }
bool empty() const { return mLength == 0; }
size_t capacity() const { return mTail.mCapacity; }
T* begin() {
MOZ_ASSERT(!mEntered);
return mBegin;
}
const T* begin() const {
MOZ_ASSERT(!mEntered);
return mBegin;
}
T* end() {
MOZ_ASSERT(!mEntered);
return mBegin + mLength;
}
const T* end() const {
MOZ_ASSERT(!mEntered);
return mBegin + mLength;
}
T& operator[](size_t aIndex) {
MOZ_ASSERT(!mEntered);
MOZ_ASSERT(aIndex < mLength);
return begin()[aIndex];
}
const T& operator[](size_t aIndex) const {
MOZ_ASSERT(!mEntered);
MOZ_ASSERT(aIndex < mLength);
return begin()[aIndex];
}
T& back() {
MOZ_ASSERT(!mEntered);
MOZ_ASSERT(!empty());
return *(end() - 1);
}
const T& back() const {
MOZ_ASSERT(!mEntered);
MOZ_ASSERT(!empty());
return *(end() - 1);
}
operator mozilla::Span<const T>() const {
return mozilla::MakeSpan(mBegin, mLength);
}
operator mozilla::Span<T>() { return mozilla::MakeSpan(mBegin, mLength); }
class Range {
friend class Vector;
T* mCur;
T* mEnd;
Range(T* aCur, T* aEnd) : mCur(aCur), mEnd(aEnd) {
MOZ_ASSERT(aCur <= aEnd);
}
public:
bool empty() const { return mCur == mEnd; }
size_t remain() const { return PointerRangeSize(mCur, mEnd); }
T& front() const {
MOZ_ASSERT(!empty());
return *mCur;
}
void popFront() {
MOZ_ASSERT(!empty());
++mCur;
}
T popCopyFront() {
MOZ_ASSERT(!empty());
return *mCur++;
}
};
class ConstRange {
friend class Vector;
const T* mCur;
const T* mEnd;
ConstRange(const T* aCur, const T* aEnd) : mCur(aCur), mEnd(aEnd) {
MOZ_ASSERT(aCur <= aEnd);
}
public:
bool empty() const { return mCur == mEnd; }
size_t remain() const { return PointerRangeSize(mCur, mEnd); }
const T& front() const {
MOZ_ASSERT(!empty());
return *mCur;
}
void popFront() {
MOZ_ASSERT(!empty());
++mCur;
}
T popCopyFront() {
MOZ_ASSERT(!empty());
return *mCur++;
}
};
Range all() { return Range(begin(), end()); }
ConstRange all() const { return ConstRange(begin(), end()); }
/* mutators */
/**
* Reverse the order of the elements in the vector in place.
*/
void reverse();
/**
* Given that the vector is empty, grow the internal capacity to |aRequest|,
* keeping the length 0.
*/
MOZ_MUST_USE bool initCapacity(size_t aRequest);
/**
* Given that the vector is empty, grow the internal capacity and length to
* |aRequest| leaving the elements' memory completely uninitialized (with all
* the associated hazards and caveats). This avoids the usual allocation-size
* rounding that happens in resize and overhead of initialization for elements
* that are about to be overwritten.
*/
MOZ_MUST_USE bool initLengthUninitialized(size_t aRequest);
/**
* If reserve(aRequest) succeeds and |aRequest >= length()|, then appending
* |aRequest - length()| elements, in any sequence of append/appendAll calls,
* is guaranteed to succeed.
*
* A request to reserve an amount less than the current length does not affect
* reserved space.
*/
MOZ_MUST_USE bool reserve(size_t aRequest);
/**
* Destroy elements in the range [end() - aIncr, end()). Does not deallocate
* or unreserve storage for those elements.
*/
void shrinkBy(size_t aIncr);
/**
* Destroy elements in the range [aNewLength, end()). Does not deallocate
* or unreserve storage for those elements.
*/
void shrinkTo(size_t aNewLength);
/** Grow the vector by aIncr elements. */
MOZ_MUST_USE bool growBy(size_t aIncr);
/** Call shrinkBy or growBy based on whether newSize > length(). */
MOZ_MUST_USE bool resize(size_t aNewLength);
/**
* Increase the length of the vector, but don't initialize the new elements
* -- leave them as uninitialized memory.
*/
MOZ_MUST_USE bool growByUninitialized(size_t aIncr);
void infallibleGrowByUninitialized(size_t aIncr);
MOZ_MUST_USE bool resizeUninitialized(size_t aNewLength);
/** Shorthand for shrinkBy(length()). */
void clear();
/** Clears and releases any heap-allocated storage. */
void clearAndFree();
/**
* Shrinks the storage to drop excess capacity if possible.
*
* The return value indicates whether the operation succeeded, otherwise, it
* represents an OOM. The bool can be safely ignored unless you want to
* provide the guarantee that `length() == capacity()`.
*
* For PODs, it calls the AllocPolicy's pod_realloc. For non-PODs, it moves
* the elements into the new storage.
*/
bool shrinkStorageToFit();
/**
* If true, appending |aNeeded| elements won't reallocate elements storage.
* This *doesn't* mean that infallibleAppend may be used! You still must
* reserve the extra space, even if this method indicates that appends won't
* need to reallocate elements storage.
*/
bool canAppendWithoutRealloc(size_t aNeeded) const;
/** Potentially fallible append operations. */
/**
* This can take either a T& or a T&&. Given a T&&, it moves |aU| into the
* vector, instead of copying it. If it fails, |aU| is left unmoved. ("We are
* not amused.")
*/
template <typename U>
MOZ_MUST_USE bool append(U&& aU);
/**
* Construct a T in-place as a new entry at the end of this vector.
*/
template <typename... Args>
MOZ_MUST_USE bool emplaceBack(Args&&... aArgs) {
if (!growByUninitialized(1)) return false;
Impl::new_(&back(), std::forward<Args>(aArgs)...);
return true;
}
template <typename U, size_t O, class BP>
MOZ_MUST_USE bool appendAll(const Vector<U, O, BP>& aU);
MOZ_MUST_USE bool appendN(const T& aT, size_t aN);
template <typename U>
MOZ_MUST_USE bool append(const U* aBegin, const U* aEnd);
template <typename U>
MOZ_MUST_USE bool append(const U* aBegin, size_t aLength);
/*
* Guaranteed-infallible append operations for use upon vectors whose
* memory has been pre-reserved. Don't use this if you haven't reserved the
* memory!
*/
template <typename U>
void infallibleAppend(U&& aU) {
internalAppend(std::forward<U>(aU));
}
void infallibleAppendN(const T& aT, size_t aN) { internalAppendN(aT, aN); }
template <typename U>
void infallibleAppend(const U* aBegin, const U* aEnd) {
internalAppend(aBegin, PointerRangeSize(aBegin, aEnd));
}
template <typename U>
void infallibleAppend(const U* aBegin, size_t aLength) {
internalAppend(aBegin, aLength);
}
template <typename... Args>
void infallibleEmplaceBack(Args&&... aArgs) {
infallibleGrowByUninitialized(1);
Impl::new_(&back(), std::forward<Args>(aArgs)...);
}
void popBack();
T popCopy();
/**
* If elements are stored in-place, return nullptr and leave this vector
* unmodified.
*
* Otherwise return this vector's elements buffer, and clear this vector as if
* by clearAndFree(). The caller now owns the buffer and is responsible for
* deallocating it consistent with this vector's AllocPolicy.
*
* N.B. Although a T*, only the range [0, length()) is constructed.
*/
MOZ_MUST_USE T* extractRawBuffer();
/**
* If elements are stored in-place, allocate a new buffer, move this vector's
* elements into it, and return that buffer.
*
* Otherwise return this vector's elements buffer. The caller now owns the
* buffer and is responsible for deallocating it consistent with this vector's
* AllocPolicy.
*
* This vector is cleared, as if by clearAndFree(), when this method
* succeeds. This method fails and returns nullptr only if new elements buffer
* allocation fails.
*
* N.B. Only the range [0, length()) of the returned buffer is constructed.
* If any of these elements are uninitialized (as growByUninitialized
* enables), behavior is undefined.
*/
MOZ_MUST_USE T* extractOrCopyRawBuffer();
/**
* Transfer ownership of an array of objects into the vector. The caller
* must have allocated the array in accordance with this vector's
* AllocPolicy.
*
* N.B. This call assumes that there are no uninitialized elements in the
* passed range [aP, aP + aLength). The range [aP + aLength, aP +
* aCapacity) must be allocated uninitialized memory.
*/
void replaceRawBuffer(T* aP, size_t aLength, size_t aCapacity);
/**
* Transfer ownership of an array of objects into the vector. The caller
* must have allocated the array in accordance with this vector's
* AllocPolicy.
*
* N.B. This call assumes that there are no uninitialized elements in the
* passed array.
*/
void replaceRawBuffer(T* aP, size_t aLength);
/**
* Places |aVal| at position |aP|, shifting existing elements from |aP| onward
* one position higher. On success, |aP| should not be reused because it'll
* be a dangling pointer if reallocation of the vector storage occurred; the
* return value should be used instead. On failure, nullptr is returned.
*
* Example usage:
*
* if (!(p = vec.insert(p, val))) {
* <handle failure>
* }
* <keep working with p>
*
* This is inherently a linear-time operation. Be careful!
*/
template <typename U>
MOZ_MUST_USE T* insert(T* aP, U&& aVal);
/**
* Removes the element |aT|, which must fall in the bounds [begin, end),
* shifting existing elements from |aT + 1| onward one position lower.
*/
void erase(T* aT);
/**
* Removes the elements [|aBegin|, |aEnd|), which must fall in the bounds
* [begin, end), shifting existing elements from |aEnd| onward to aBegin's old
* position.
*/
void erase(T* aBegin, T* aEnd);
/**
* Removes all elements that satisfy the predicate, shifting existing elements
* lower to fill erased gaps.
*/
template <typename Pred>
void eraseIf(Pred aPred);
/**
* Removes all elements that compare equal to |aU|, shifting existing elements
* lower to fill erased gaps.
*/
template <typename U>
void eraseIfEqual(const U& aU);
/**
* Measure the size of the vector's heap-allocated storage.
*/
size_t sizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const;
/**
* Like sizeOfExcludingThis, but also measures the size of the vector
* object (which must be heap-allocated) itself.
*/
size_t sizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
void swap(Vector& aOther);
private:
Vector(const Vector&) = delete;
void operator=(const Vector&) = delete;
};
/* This does the re-entrancy check plus several other sanity checks. */
#define MOZ_REENTRANCY_GUARD_ET_AL \
ReentrancyGuard g(*this); \
MOZ_ASSERT_IF(usingInlineStorage(), mTail.mCapacity == kInlineCapacity); \
MOZ_ASSERT(reserved() <= mTail.mCapacity); \
MOZ_ASSERT(mLength <= reserved()); \
MOZ_ASSERT(mLength <= mTail.mCapacity)
/* Vector Implementation */
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE Vector<T, N, AP>::Vector(AP aAP)
: AP(std::move(aAP)),
mLength(0),
mTail(kInlineCapacity, 0)
#ifdef DEBUG
,
mEntered(false)
#endif
{
mBegin = inlineStorage();
}
/* Move constructor. */
template <typename T, size_t N, class AllocPolicy>
MOZ_ALWAYS_INLINE Vector<T, N, AllocPolicy>::Vector(Vector&& aRhs)
: AllocPolicy(std::move(aRhs))
#ifdef DEBUG
,
mEntered(false)
#endif
{
mLength = aRhs.mLength;
mTail.mCapacity = aRhs.mTail.mCapacity;
#ifdef DEBUG
mTail.mReserved = aRhs.mTail.mReserved;
#endif
if (aRhs.usingInlineStorage()) {
/* We can't move the buffer over in this case, so copy elements. */
mBegin = inlineStorage();
Impl::moveConstruct(mBegin, aRhs.beginNoCheck(), aRhs.endNoCheck());
/*
* Leave aRhs's mLength, mBegin, mCapacity, and mReserved as they are.
* The elements in its in-line storage still need to be destroyed.
*/
} else {
/*
* Take src's buffer, and turn src into an empty vector using
* in-line storage.
*/
mBegin = aRhs.mBegin;
aRhs.mBegin = aRhs.inlineStorage();
aRhs.mTail.mCapacity = kInlineCapacity;
aRhs.mLength = 0;
#ifdef DEBUG
aRhs.mTail.mReserved = 0;
#endif
}
}
/* Move assignment. */
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE Vector<T, N, AP>& Vector<T, N, AP>::operator=(Vector&& aRhs) {
MOZ_ASSERT(this != &aRhs, "self-move assignment is prohibited");
this->~Vector();
new (KnownNotNull, this) Vector(std::move(aRhs));
return *this;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE Vector<T, N, AP>::~Vector() {
MOZ_REENTRANCY_GUARD_ET_AL;
Impl::destroy(beginNoCheck(), endNoCheck());
if (!usingInlineStorage()) {
this->free_(beginNoCheck(), mTail.mCapacity);
}
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::reverse() {
MOZ_REENTRANCY_GUARD_ET_AL;
T* elems = mBegin;
size_t len = mLength;
size_t mid = len / 2;
for (size_t i = 0; i < mid; i++) {
std::swap(elems[i], elems[len - i - 1]);
}
}
/*
* This function will create a new heap buffer with capacity aNewCap,
* move all elements in the inline buffer to this new buffer,
* and fail on OOM.
*/
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::convertToHeapStorage(size_t aNewCap) {
MOZ_ASSERT(usingInlineStorage());
/* Allocate buffer. */
MOZ_ASSERT(!detail::CapacityHasExcessSpace<T>(aNewCap));
T* newBuf = this->template pod_malloc<T>(aNewCap);
if (MOZ_UNLIKELY(!newBuf)) {
return false;
}
/* Copy inline elements into heap buffer. */
Impl::moveConstruct(newBuf, beginNoCheck(), endNoCheck());
Impl::destroy(beginNoCheck(), endNoCheck());
/* Switch in heap buffer. */
mBegin = newBuf;
/* mLength is unchanged. */
mTail.mCapacity = aNewCap;
return true;
}
template <typename T, size_t N, class AP>
MOZ_NEVER_INLINE bool Vector<T, N, AP>::growStorageBy(size_t aIncr) {
MOZ_ASSERT(mLength + aIncr > mTail.mCapacity);
/*
* When choosing a new capacity, its size should is as close to 2**N bytes
* as possible. 2**N-sized requests are best because they are unlikely to
* be rounded up by the allocator. Asking for a 2**N number of elements
* isn't as good, because if sizeof(T) is not a power-of-two that would
* result in a non-2**N request size.
*/
size_t newCap;
if (aIncr == 1) {
if (usingInlineStorage()) {
/* This case occurs in ~70--80% of the calls to this function. */
size_t newSize =
tl::RoundUpPow2<(kInlineCapacity + 1) * sizeof(T)>::value;
newCap = newSize / sizeof(T);
goto convert;
}
if (mLength == 0) {
/* This case occurs in ~0--10% of the calls to this function. */
newCap = 1;
goto grow;
}
/* This case occurs in ~15--20% of the calls to this function. */
/*
* Will mLength * 4 *sizeof(T) overflow? This condition limits a vector
* to 1GB of memory on a 32-bit system, which is a reasonable limit. It
* also ensures that
*
* static_cast<char*>(end()) - static_cast<char*>(begin())
*
* doesn't overflow ptrdiff_t (see bug 510319).
*/
if (MOZ_UNLIKELY(mLength & tl::MulOverflowMask<4 * sizeof(T)>::value)) {
this->reportAllocOverflow();
return false;
}
/*
* If we reach here, the existing capacity will have a size that is already
* as close to 2^N as sizeof(T) will allow. Just double the capacity, and
* then there might be space for one more element.
*/
newCap = mLength * 2;
if (detail::CapacityHasExcessSpace<T>(newCap)) {
newCap += 1;
}
} else {
/* This case occurs in ~2% of the calls to this function. */
size_t newMinCap = mLength + aIncr;
/* Did mLength + aIncr overflow? Will newCap * sizeof(T) overflow? */
if (MOZ_UNLIKELY(newMinCap < mLength ||
newMinCap & tl::MulOverflowMask<2 * sizeof(T)>::value)) {
this->reportAllocOverflow();
return false;
}
size_t newMinSize = newMinCap * sizeof(T);
size_t newSize = RoundUpPow2(newMinSize);
newCap = newSize / sizeof(T);
}
if (usingInlineStorage()) {
convert:
return convertToHeapStorage(newCap);
}
grow:
return Impl::growTo(*this, newCap);
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::initCapacity(size_t aRequest) {
MOZ_ASSERT(empty());
MOZ_ASSERT(usingInlineStorage());
if (aRequest == 0) {
return true;
}
T* newbuf = this->template pod_malloc<T>(aRequest);
if (MOZ_UNLIKELY(!newbuf)) {
return false;
}
mBegin = newbuf;
mTail.mCapacity = aRequest;
#ifdef DEBUG
mTail.mReserved = aRequest;
#endif
return true;
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::initLengthUninitialized(size_t aRequest) {
if (!initCapacity(aRequest)) {
return false;
}
infallibleGrowByUninitialized(aRequest);
return true;
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::maybeCheckSimulatedOOM(size_t aRequestedSize) {
if (aRequestedSize <= N) {
return true;
}
#ifdef DEBUG
if (aRequestedSize <= mTail.mReserved) {
return true;
}
#endif
return allocPolicy().checkSimulatedOOM();
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::reserve(size_t aRequest) {
MOZ_REENTRANCY_GUARD_ET_AL;
if (aRequest > mTail.mCapacity) {
if (MOZ_UNLIKELY(!growStorageBy(aRequest - mLength))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(aRequest)) {
return false;
}
#ifdef DEBUG
if (aRequest > mTail.mReserved) {
mTail.mReserved = aRequest;
}
MOZ_ASSERT(mLength <= mTail.mReserved);
MOZ_ASSERT(mTail.mReserved <= mTail.mCapacity);
#endif
return true;
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::shrinkBy(size_t aIncr) {
MOZ_REENTRANCY_GUARD_ET_AL;
MOZ_ASSERT(aIncr <= mLength);
Impl::destroy(endNoCheck() - aIncr, endNoCheck());
mLength -= aIncr;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::shrinkTo(size_t aNewLength) {
MOZ_ASSERT(aNewLength <= mLength);
shrinkBy(mLength - aNewLength);
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::growBy(size_t aIncr) {
MOZ_REENTRANCY_GUARD_ET_AL;
if (aIncr > mTail.mCapacity - mLength) {
if (MOZ_UNLIKELY(!growStorageBy(aIncr))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(mLength + aIncr)) {
return false;
}
MOZ_ASSERT(mLength + aIncr <= mTail.mCapacity);
T* newend = endNoCheck() + aIncr;
Impl::initialize(endNoCheck(), newend);
mLength += aIncr;
#ifdef DEBUG
if (mLength > mTail.mReserved) {
mTail.mReserved = mLength;
}
#endif
return true;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::growByUninitialized(size_t aIncr) {
MOZ_REENTRANCY_GUARD_ET_AL;
if (aIncr > mTail.mCapacity - mLength) {
if (MOZ_UNLIKELY(!growStorageBy(aIncr))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(mLength + aIncr)) {
return false;
}
#ifdef DEBUG
if (mLength + aIncr > mTail.mReserved) {
mTail.mReserved = mLength + aIncr;
}
#endif
infallibleGrowByUninitialized(aIncr);
return true;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::infallibleGrowByUninitialized(
size_t aIncr) {
MOZ_ASSERT(mLength + aIncr <= reserved());
mLength += aIncr;
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::resize(size_t aNewLength) {
size_t curLength = mLength;
if (aNewLength > curLength) {
return growBy(aNewLength - curLength);
}
shrinkBy(curLength - aNewLength);
return true;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::resizeUninitialized(
size_t aNewLength) {
size_t curLength = mLength;
if (aNewLength > curLength) {
return growByUninitialized(aNewLength - curLength);
}
shrinkBy(curLength - aNewLength);
return true;
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::clear() {
MOZ_REENTRANCY_GUARD_ET_AL;
Impl::destroy(beginNoCheck(), endNoCheck());
mLength = 0;
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::clearAndFree() {
clear();
if (usingInlineStorage()) {
return;
}
this->free_(beginNoCheck(), mTail.mCapacity);
mBegin = inlineStorage();
mTail.mCapacity = kInlineCapacity;
#ifdef DEBUG
mTail.mReserved = 0;
#endif
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::shrinkStorageToFit() {
MOZ_REENTRANCY_GUARD_ET_AL;
const auto length = this->length();
if (usingInlineStorage() || length == capacity()) {
return true;
}
if (!length) {
this->free_(beginNoCheck(), mTail.mCapacity);
mBegin = inlineStorage();
mTail.mCapacity = kInlineCapacity;
#ifdef DEBUG
mTail.mReserved = 0;
#endif
return true;
}
T* newBuf;
size_t newCap;
if (length <= kInlineCapacity) {
newBuf = inlineStorage();
newCap = kInlineCapacity;
} else {
if (kElemIsPod) {
newBuf = this->template pod_realloc<T>(beginNoCheck(), mTail.mCapacity,
length);
} else {
newBuf = this->template pod_malloc<T>(length);
}
if (MOZ_UNLIKELY(!newBuf)) {
return false;
}
newCap = length;
}
if (!kElemIsPod || newBuf == inlineStorage()) {
Impl::moveConstruct(newBuf, beginNoCheck(), endNoCheck());
Impl::destroy(beginNoCheck(), endNoCheck());
}
if (!kElemIsPod) {
this->free_(beginNoCheck(), mTail.mCapacity);
}
mBegin = newBuf;
mTail.mCapacity = newCap;
#ifdef DEBUG
mTail.mReserved = length;
#endif
return true;
}
template <typename T, size_t N, class AP>
inline bool Vector<T, N, AP>::canAppendWithoutRealloc(size_t aNeeded) const {
return mLength + aNeeded <= mTail.mCapacity;
}
template <typename T, size_t N, class AP>
template <typename U, size_t O, class BP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::internalAppendAll(
const Vector<U, O, BP>& aOther) {
internalAppend(aOther.begin(), aOther.length());
}
template <typename T, size_t N, class AP>
template <typename U>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::internalAppend(U&& aU) {
MOZ_ASSERT(mLength + 1 <= mTail.mReserved);
MOZ_ASSERT(mTail.mReserved <= mTail.mCapacity);
Impl::new_(endNoCheck(), std::forward<U>(aU));
++mLength;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::appendN(const T& aT, size_t aNeeded) {
MOZ_REENTRANCY_GUARD_ET_AL;
if (mLength + aNeeded > mTail.mCapacity) {
if (MOZ_UNLIKELY(!growStorageBy(aNeeded))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(mLength + aNeeded)) {
return false;
}
#ifdef DEBUG
if (mLength + aNeeded > mTail.mReserved) {
mTail.mReserved = mLength + aNeeded;
}
#endif
internalAppendN(aT, aNeeded);
return true;
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::internalAppendN(const T& aT,
size_t aNeeded) {
MOZ_ASSERT(mLength + aNeeded <= mTail.mReserved);
MOZ_ASSERT(mTail.mReserved <= mTail.mCapacity);
Impl::copyConstructN(endNoCheck(), aNeeded, aT);
mLength += aNeeded;
}
template <typename T, size_t N, class AP>
template <typename U>
inline T* Vector<T, N, AP>::insert(T* aP, U&& aVal) {
MOZ_ASSERT(begin() <= aP);
MOZ_ASSERT(aP <= end());
size_t pos = aP - begin();
MOZ_ASSERT(pos <= mLength);
size_t oldLength = mLength;
if (pos == oldLength) {
if (!append(std::forward<U>(aVal))) {
return nullptr;
}
} else {
T oldBack = std::move(back());
if (!append(std::move(oldBack))) {
return nullptr;
}
for (size_t i = oldLength - 1; i > pos; --i) {
(*this)[i] = std::move((*this)[i - 1]);
}
(*this)[pos] = std::forward<U>(aVal);
}
return begin() + pos;
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::erase(T* aIt) {
MOZ_ASSERT(begin() <= aIt);
MOZ_ASSERT(aIt < end());
while (aIt + 1 < end()) {
*aIt = std::move(*(aIt + 1));
++aIt;
}
popBack();
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::erase(T* aBegin, T* aEnd) {
MOZ_ASSERT(begin() <= aBegin);
MOZ_ASSERT(aBegin <= aEnd);
MOZ_ASSERT(aEnd <= end());
while (aEnd < end()) {
*aBegin++ = std::move(*aEnd++);
}
shrinkBy(aEnd - aBegin);
}
template <typename T, size_t N, class AP>
template <typename Pred>
void Vector<T, N, AP>::eraseIf(Pred aPred) {
// remove_if finds the first element to be erased, and then efficiently move-
// assigns elements to effectively overwrite elements that satisfy the
// predicate. It returns the new end pointer, after which there are only
// moved-from elements ready to be destroyed, so we just need to shrink the
// vector accordingly.
T* newEnd = std::remove_if(begin(), end(),
[&aPred](const T& aT) { return aPred(aT); });
MOZ_ASSERT(newEnd <= end());
shrinkBy(end() - newEnd);
}
template <typename T, size_t N, class AP>
template <typename U>
void Vector<T, N, AP>::eraseIfEqual(const U& aU) {
return eraseIf([&aU](const T& aT) { return aT == aU; });
}
template <typename T, size_t N, class AP>
template <typename U>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::append(const U* aInsBegin,
const U* aInsEnd) {
MOZ_REENTRANCY_GUARD_ET_AL;
size_t aNeeded = PointerRangeSize(aInsBegin, aInsEnd);
if (mLength + aNeeded > mTail.mCapacity) {
if (MOZ_UNLIKELY(!growStorageBy(aNeeded))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(mLength + aNeeded)) {
return false;
}
#ifdef DEBUG
if (mLength + aNeeded > mTail.mReserved) {
mTail.mReserved = mLength + aNeeded;
}
#endif
internalAppend(aInsBegin, aNeeded);
return true;
}
template <typename T, size_t N, class AP>
template <typename U>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::internalAppend(const U* aInsBegin,
size_t aInsLength) {
MOZ_ASSERT(mLength + aInsLength <= mTail.mReserved);
MOZ_ASSERT(mTail.mReserved <= mTail.mCapacity);
Impl::copyConstruct(endNoCheck(), aInsBegin, aInsBegin + aInsLength);
mLength += aInsLength;
}
template <typename T, size_t N, class AP>
template <typename U>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::append(U&& aU) {
MOZ_REENTRANCY_GUARD_ET_AL;
if (mLength == mTail.mCapacity) {
if (MOZ_UNLIKELY(!growStorageBy(1))) {
return false;
}
} else if (!maybeCheckSimulatedOOM(mLength + 1)) {
return false;
}
#ifdef DEBUG
if (mLength + 1 > mTail.mReserved) {
mTail.mReserved = mLength + 1;
}
#endif
internalAppend(std::forward<U>(aU));
return true;
}
template <typename T, size_t N, class AP>
template <typename U, size_t O, class BP>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::appendAll(
const Vector<U, O, BP>& aOther) {
return append(aOther.begin(), aOther.length());
}
template <typename T, size_t N, class AP>
template <class U>
MOZ_ALWAYS_INLINE bool Vector<T, N, AP>::append(const U* aInsBegin,
size_t aInsLength) {
return append(aInsBegin, aInsBegin + aInsLength);
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE void Vector<T, N, AP>::popBack() {
MOZ_REENTRANCY_GUARD_ET_AL;
MOZ_ASSERT(!empty());
--mLength;
endNoCheck()->~T();
}
template <typename T, size_t N, class AP>
MOZ_ALWAYS_INLINE T Vector<T, N, AP>::popCopy() {
T ret = back();
popBack();
return ret;
}
template <typename T, size_t N, class AP>
inline T* Vector<T, N, AP>::extractRawBuffer() {
MOZ_REENTRANCY_GUARD_ET_AL;
if (usingInlineStorage()) {
return nullptr;
}
T* ret = mBegin;
mBegin = inlineStorage();
mLength = 0;
mTail.mCapacity = kInlineCapacity;
#ifdef DEBUG
mTail.mReserved = 0;
#endif
return ret;
}
template <typename T, size_t N, class AP>
inline T* Vector<T, N, AP>::extractOrCopyRawBuffer() {
if (T* ret = extractRawBuffer()) {
return ret;
}
MOZ_REENTRANCY_GUARD_ET_AL;
T* copy = this->template pod_malloc<T>(mLength);
if (!copy) {
return nullptr;
}
Impl::moveConstruct(copy, beginNoCheck(), endNoCheck());
Impl::destroy(beginNoCheck(), endNoCheck());
mBegin = inlineStorage();
mLength = 0;
mTail.mCapacity = kInlineCapacity;
#ifdef DEBUG
mTail.mReserved = 0;
#endif
return copy;
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::replaceRawBuffer(T* aP, size_t aLength,
size_t aCapacity) {
MOZ_REENTRANCY_GUARD_ET_AL;
/* Destroy what we have. */
Impl::destroy(beginNoCheck(), endNoCheck());
if (!usingInlineStorage()) {
this->free_(beginNoCheck(), mTail.mCapacity);
}
/* Take in the new buffer. */
if (aCapacity <= kInlineCapacity) {
/*
* We convert to inline storage if possible, even though aP might
* otherwise be acceptable. Maybe this behaviour should be
* specifiable with an argument to this function.
*/
mBegin = inlineStorage();
mLength = aLength;
mTail.mCapacity = kInlineCapacity;
Impl::moveConstruct(mBegin, aP, aP + aLength);
Impl::destroy(aP, aP + aLength);
this->free_(aP, aCapacity);
} else {
mBegin = aP;
mLength = aLength;
mTail.mCapacity = aCapacity;
}
#ifdef DEBUG
mTail.mReserved = aCapacity;
#endif
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::replaceRawBuffer(T* aP, size_t aLength) {
replaceRawBuffer(aP, aLength, aLength);
}
template <typename T, size_t N, class AP>
inline size_t Vector<T, N, AP>::sizeOfExcludingThis(
MallocSizeOf aMallocSizeOf) const {
return usingInlineStorage() ? 0 : aMallocSizeOf(beginNoCheck());
}
template <typename T, size_t N, class AP>
inline size_t Vector<T, N, AP>::sizeOfIncludingThis(
MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(this) + sizeOfExcludingThis(aMallocSizeOf);
}
template <typename T, size_t N, class AP>
inline void Vector<T, N, AP>::swap(Vector& aOther) {
static_assert(N == 0, "still need to implement this for N != 0");
// This only works when inline storage is always empty.
if (!usingInlineStorage() && aOther.usingInlineStorage()) {
aOther.mBegin = mBegin;
mBegin = inlineStorage();
} else if (usingInlineStorage() && !aOther.usingInlineStorage()) {
mBegin = aOther.mBegin;
aOther.mBegin = aOther.inlineStorage();
} else if (!usingInlineStorage() && !aOther.usingInlineStorage()) {
std::swap(mBegin, aOther.mBegin);
} else {
// This case is a no-op, since we'd set both to use their inline storage.
}
std::swap(mLength, aOther.mLength);
std::swap(mTail.mCapacity, aOther.mTail.mCapacity);
#ifdef DEBUG
std::swap(mTail.mReserved, aOther.mTail.mReserved);
#endif
}
} // namespace mozilla
#endif /* mozilla_Vector_h */