EIC code displayed by LXR master/​include/​QtCore/​qarraydataops.h	Source navigation Diff markup Identifier search General search
	Version: master test Revert   Change

File indexing completed on 2026-07-31 09:15:22

 // Copyright (C) 2020 The Qt Company Ltd.
 // Copyright (C) 2016 Intel Corporation.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 // Qt-Security score:significant reason:default
 
 #ifndef QARRAYDATAOPS_H
 #define QARRAYDATAOPS_H
 
 #include <QtCore/qarraydata.h>
 #include <QtCore/qcontainertools_impl.h>
 #include <QtCore/qnamespace.h>
 
 #include <QtCore/q20functional.h>
 #include <QtCore/q20memory.h>
 #include <new>
 #include <string.h>
 #include <utility>
 #include <iterator>
 #include <type_traits>
 
 QT_BEGIN_NAMESPACE
 
 template <class T> struct QArrayDataPointer;
 
 namespace QtPrivate {
 
 template <class T>
 struct QPodArrayOps
         : public QArrayDataPointer<T>
 {
     static_assert (std::is_nothrow_destructible_v<T>, "Types with throwing destructors are not supported in Qt containers.");
 
 protected:
     typedef QTypedArrayData<T> Data;
     using DataPointer = QArrayDataPointer<T>;
 
 public:
     typedef typename QArrayDataPointer<T>::parameter_type parameter_type;
 
     using QArrayDataPointer<T>::QArrayDataPointer;
 
     void copyAppend(const T *b, const T *e) noexcept
     {
         Q_ASSERT(this->isMutable() || b == e);
         Q_ASSERT(!this->isShared() || b == e);
         Q_ASSERT(b <= e);
         Q_ASSERT((e - b) <= this->freeSpaceAtEnd());
 
         if (b == e)
             return;
 
         ::memcpy(static_cast<void *>(this->end()), static_cast<const void *>(b), (e - b) * sizeof(T));
         this->size += (e - b);
     }
 
     void copyAppend(qsizetype n, parameter_type t) noexcept
     {
         Q_ASSERT(!this->isShared() || n == 0);
         Q_ASSERT(this->freeSpaceAtEnd() >= n);
         if (!n)
             return;
 
         T *where = this->end();
         this->size += qsizetype(n);
         while (n--)
             *where++ = t;
     }
 
     void moveAppend(T *b, T *e) noexcept
     {
         copyAppend(b, e);
     }
 
     void truncate(size_t newSize) noexcept
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(!this->isShared());
         Q_ASSERT(newSize <= size_t(this->size));
 
         this->size = qsizetype(newSize);
     }
 
     void destroyAll() noexcept // Call from destructors, ONLY!
     {
         Q_ASSERT(this->d);
         Q_ASSERT(this->d->ref_.loadRelaxed() == 0);
 
         // As this is to be called only from destructor, it doesn't need to be
         // exception safe; size not updated.
     }
 
     T *createHole(QArrayData::GrowthPosition pos, qsizetype where, qsizetype n)
     {
         Q_ASSERT((pos == QArrayData::GrowsAtBeginning && n <= this->freeSpaceAtBegin()) ||
                  (pos == QArrayData::GrowsAtEnd && n <= this->freeSpaceAtEnd()));
 
         T *insertionPoint = this->ptr + where;
         if (pos == QArrayData::GrowsAtEnd) {
             if (where < this->size)
                 ::memmove(static_cast<void *>(insertionPoint + n), static_cast<void *>(insertionPoint), (this->size - where) * sizeof(T));
         } else {
             Q_ASSERT(where == 0);
             this->ptr -= n;
             insertionPoint -= n;
         }
         this->size += n;
         return insertionPoint;
     }
 
     void insert(qsizetype i, const T *data, qsizetype n)
     {
         typename Data::GrowthPosition pos = Data::GrowsAtEnd;
         if (this->size != 0 && i == 0)
             pos = Data::GrowsAtBeginning;
 
         DataPointer oldData;
         this->detachAndGrow(pos, n, &data, &oldData);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         T *where = createHole(pos, i, n);
         ::memcpy(static_cast<void *>(where), static_cast<const void *>(data), n * sizeof(T));
     }
 
     void insert(qsizetype i, qsizetype n, parameter_type t)
     {
         T copy(t);
 
         typename Data::GrowthPosition pos = Data::GrowsAtEnd;
         if (this->size != 0 && i == 0)
             pos = Data::GrowsAtBeginning;
 
         this->detachAndGrow(pos, n, nullptr, nullptr);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         T *where = createHole(pos, i, n);
         while (n--)
             *where++ = copy;
     }
 
     template<typename... Args>
     void emplace(qsizetype i, Args &&... args)
     {
         bool detach = this->needsDetach();
         if (!detach) {
             if (i == this->size && this->freeSpaceAtEnd()) {
                 new (this->end()) T(std::forward<Args>(args)...);
                 ++this->size;
                 return;
             }
             if (i == 0 && this->freeSpaceAtBegin()) {
                 new (this->begin() - 1) T(std::forward<Args>(args)...);
                 --this->ptr;
                 ++this->size;
                 return;
             }
         }
         T tmp(std::forward<Args>(args)...);
         typename QArrayData::GrowthPosition pos = QArrayData::GrowsAtEnd;
         if (this->size != 0 && i == 0)
             pos = QArrayData::GrowsAtBeginning;
 
         this->detachAndGrow(pos, 1, nullptr, nullptr);
 
         T *where = createHole(pos, i, 1);
         new (where) T(std::move(tmp));
     }
 
     void erase(T *b, qsizetype n)
     {
         T *e = b + n;
         Q_ASSERT(this->isMutable());
         Q_ASSERT(b < e);
         Q_ASSERT(b >= this->begin() && b < this->end());
         Q_ASSERT(e > this->begin() && e <= this->end());
 
         // Comply with std::vector::erase(): erased elements and all after them
         // are invalidated. However, erasing from the beginning effectively
         // means that all iterators are invalidated. We can use this freedom to
         // erase by moving towards the end.
         if (b == this->begin() && e != this->end()) {
             this->ptr = e;
         } else if (e != this->end()) {
             ::memmove(static_cast<void *>(b), static_cast<void *>(e),
                       (static_cast<T *>(this->end()) - e) * sizeof(T));
         }
         this->size -= n;
     }
 
     void eraseFirst() noexcept
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(this->size);
         ++this->ptr;
         --this->size;
     }
 
     void eraseLast() noexcept
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(this->size);
         --this->size;
     }
 
     template <typename Predicate>
     qsizetype eraseIf(Predicate pred)
     {
         qsizetype result = 0;
         if (this->size == 0)
             return result;
 
         if (!this->needsDetach()) {
             auto end = this->end();
             auto it = std::remove_if(this->begin(), end, pred);
             if (it != end) {
                 result = std::distance(it, end);
                 erase(it, result);
             }
         } else {
             const auto begin = this->begin();
             const auto end = this->end();
             auto it = std::find_if(begin, end, pred);
             if (it == end)
                 return result;
 
             QPodArrayOps<T> other(this->size);
             Q_CHECK_PTR(other.data());
             auto dest = other.begin();
             // std::uninitialized_copy will fallback to ::memcpy/memmove()
             dest = std::uninitialized_copy(begin, it, dest);
             dest = q_uninitialized_remove_copy_if(std::next(it), end, dest, pred);
             other.size = std::distance(other.data(), dest);
             result = this->size - other.size;
             this->swap(other);
         }
         return result;
     }
 
     struct Span { T *begin; T *end; };
 
     void copyRanges(std::initializer_list<Span> ranges)
     {
         auto it = this->begin();
         std::for_each(ranges.begin(), ranges.end(), [&it](const auto &span) {
             it = std::copy(span.begin, span.end, it);
         });
         this->size = std::distance(this->begin(), it);
     }
 
     void assign(T *b, T *e, parameter_type t) noexcept
     {
         Q_ASSERT(b <= e);
         Q_ASSERT(b >= this->begin() && e <= this->end());
 
         while (b != e)
             ::memcpy(static_cast<void *>(b++), static_cast<const void *>(&t), sizeof(T));
     }
 
     void reallocate(qsizetype alloc, QArrayData::AllocationOption option)
     {
         auto pair = Data::reallocateUnaligned(this->d, this->ptr, alloc, option);
         Q_CHECK_PTR(pair.second);
         Q_ASSERT(pair.first != nullptr);
         this->d = pair.first;
         this->ptr = pair.second;
     }
 };
 
 template <class T>
 struct QGenericArrayOps
         : public QArrayDataPointer<T>
 {
     static_assert (std::is_nothrow_destructible_v<T>, "Types with throwing destructors are not supported in Qt containers.");
 
 protected:
     typedef QTypedArrayData<T> Data;
     using DataPointer = QArrayDataPointer<T>;
 
 public:
     typedef typename QArrayDataPointer<T>::parameter_type parameter_type;
 
     void copyAppend(const T *b, const T *e)
     {
         Q_ASSERT(this->isMutable() || b == e);
         Q_ASSERT(!this->isShared() || b == e);
         Q_ASSERT(b <= e);
         Q_ASSERT((e - b) <= this->freeSpaceAtEnd());
 
         if (b == e) // short-cut and handling the case b and e == nullptr
             return;
 
         T *data = this->begin();
         while (b < e) {
             new (data + this->size) T(*b);
             ++b;
             ++this->size;
         }
     }
 
     void copyAppend(qsizetype n, parameter_type t)
     {
         Q_ASSERT(!this->isShared() || n == 0);
         Q_ASSERT(this->freeSpaceAtEnd() >= n);
         if (!n)
             return;
 
         T *data = this->begin();
         while (n--) {
             new (data + this->size) T(t);
             ++this->size;
         }
     }
 
     void moveAppend(T *b, T *e)
     {
         Q_ASSERT(this->isMutable() || b == e);
         Q_ASSERT(!this->isShared() || b == e);
         Q_ASSERT(b <= e);
         Q_ASSERT((e - b) <= this->freeSpaceAtEnd());
 
         if (b == e)
             return;
 
         T *data = this->begin();
         while (b < e) {
             new (data + this->size) T(std::move(*b));
             ++b;
             ++this->size;
         }
     }
 
     void truncate(size_t newSize)
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(!this->isShared());
         Q_ASSERT(newSize <= size_t(this->size));
 
         std::destroy(this->begin() + newSize, this->end());
         this->size = newSize;
     }
 
     void destroyAll() // Call from destructors, ONLY
     {
         Q_ASSERT(this->d);
         // As this is to be called only from destructor, it doesn't need to be
         // exception safe; size not updated.
 
         Q_ASSERT(this->d->ref_.loadRelaxed() == 0);
 
         std::destroy(this->begin(), this->end());
     }
 
     struct Inserter
     {
         QArrayDataPointer<T> *data;
         T *begin;
         qsizetype size;
 
         qsizetype sourceCopyConstruct = 0, nSource = 0, move = 0, sourceCopyAssign = 0;
         T *end = nullptr, *last = nullptr, *where = nullptr;
 
         Inserter(QArrayDataPointer<T> *d) : data(d)
         {
             begin = d->ptr;
             size = d->size;
         }
         ~Inserter() {
             data->ptr = begin;
             data->size = size;
         }
         Q_DISABLE_COPY(Inserter)
 
         void setup(qsizetype pos, qsizetype n)
         {
             end = begin + size;
             last = end - 1;
             where = begin + pos;
             qsizetype dist = size - pos;
             sourceCopyConstruct = 0;
             nSource = n;
             move = n - dist; // smaller 0
             sourceCopyAssign = n;
             if (n > dist) {
                 sourceCopyConstruct = n - dist;
                 move = 0;
                 sourceCopyAssign -= sourceCopyConstruct;
             }
         }
 
         void insert(qsizetype pos, const T *source, qsizetype n)
         {
             qsizetype oldSize = size;
             Q_UNUSED(oldSize);
 
             setup(pos, n);
 
             // first create new elements at the end, by copying from elements
             // to be inserted (if they extend past the current end of the array)
             for (qsizetype i = 0; i != sourceCopyConstruct; ++i) {
                 new (end + i) T(source[nSource - sourceCopyConstruct + i]);
                 ++size;
             }
             Q_ASSERT(size <= oldSize + n);
 
             // now move construct new elements at the end from existing elements inside
             // the array.
             for (qsizetype i = sourceCopyConstruct; i != nSource; ++i) {
                 new (end + i) T(std::move(*(end + i - nSource)));
                 ++size;
             }
             // array has the new size now!
             Q_ASSERT(size == oldSize + n);
 
             // now move assign existing elements towards the end
             for (qsizetype i = 0; i != move; --i)
                 last[i] = std::move(last[i - nSource]);
 
             // finally copy the remaining elements from source over
             for (qsizetype i = 0; i != sourceCopyAssign; ++i)
                 where[i] = source[i];
         }
 
         void insert(qsizetype pos, const T &t, qsizetype n)
         {
             const qsizetype oldSize = size;
             Q_UNUSED(oldSize);
 
             setup(pos, n);
 
             // first create new elements at the end, by copying from elements
             // to be inserted (if they extend past the current end of the array)
             for (qsizetype i = 0; i != sourceCopyConstruct; ++i) {
                 new (end + i) T(t);
                 ++size;
             }
             Q_ASSERT(size <= oldSize + n);
 
             // now move construct new elements at the end from existing elements inside
             // the array.
             for (qsizetype i = sourceCopyConstruct; i != nSource; ++i) {
                 new (end + i) T(std::move(*(end + i - nSource)));
                 ++size;
             }
             // array has the new size now!
             Q_ASSERT(size == oldSize + n);
 
             // now move assign existing elements towards the end
             for (qsizetype i = 0; i != move; --i)
                 last[i] = std::move(last[i - nSource]);
 
             // finally copy the remaining elements from source over
             for (qsizetype i = 0; i != sourceCopyAssign; ++i)
                 where[i] = t;
         }
 
         void insertOne(qsizetype pos, T &&t)
         {
             setup(pos, 1);
 
             if (sourceCopyConstruct) {
                 Q_ASSERT(sourceCopyConstruct == 1);
                 new (end) T(std::move(t));
                 ++size;
             } else {
                 // create a new element at the end by move constructing one existing element
                 // inside the array.
                 new (end) T(std::move(*(end - 1)));
                 ++size;
 
                 // now move assign existing elements towards the end
                 for (qsizetype i = 0; i != move; --i)
                     last[i] = std::move(last[i - 1]);
 
                 // and move the new item into place
                 *where = std::move(t);
             }
         }
     };
 
     void insert(qsizetype i, const T *data, qsizetype n)
     {
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         DataPointer oldData;
         this->detachAndGrow(pos, n, &data, &oldData);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         if (growsAtBegin) {
             // copy construct items in reverse order at the begin
             Q_ASSERT(this->freeSpaceAtBegin() >= n);
             while (n) {
                 --n;
                 new (this->begin() - 1) T(data[n]);
                 --this->ptr;
                 ++this->size;
             }
         } else {
             Inserter(this).insert(i, data, n);
         }
     }
 
     void insert(qsizetype i, qsizetype n, parameter_type t)
     {
         T copy(t);
 
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         this->detachAndGrow(pos, n, nullptr, nullptr);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         if (growsAtBegin) {
             // copy construct items in reverse order at the begin
             Q_ASSERT(this->freeSpaceAtBegin() >= n);
             while (n--) {
                 new (this->begin() - 1) T(copy);
                 --this->ptr;
                 ++this->size;
             }
         } else {
             Inserter(this).insert(i, copy, n);
         }
     }
 
     template<typename... Args>
     void emplace(qsizetype i, Args &&... args)
     {
         bool detach = this->needsDetach();
         if (!detach) {
             if (i == this->size && this->freeSpaceAtEnd()) {
                 new (this->end()) T(std::forward<Args>(args)...);
                 ++this->size;
                 return;
             }
             if (i == 0 && this->freeSpaceAtBegin()) {
                 new (this->begin() - 1) T(std::forward<Args>(args)...);
                 --this->ptr;
                 ++this->size;
                 return;
             }
         }
         T tmp(std::forward<Args>(args)...);
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         this->detachAndGrow(pos, 1, nullptr, nullptr);
 
         if (growsAtBegin) {
             Q_ASSERT(this->freeSpaceAtBegin());
             new (this->begin() - 1) T(std::move(tmp));
             --this->ptr;
             ++this->size;
         } else {
             Inserter(this).insertOne(i, std::move(tmp));
         }
     }
 
     void erase(T *b, qsizetype n)
     {
         T *e = b + n;
         Q_ASSERT(this->isMutable());
         Q_ASSERT(b < e);
         Q_ASSERT(b >= this->begin() && b < this->end());
         Q_ASSERT(e > this->begin() && e <= this->end());
 
         // Comply with std::vector::erase(): erased elements and all after them
         // are invalidated. However, erasing from the beginning effectively
         // means that all iterators are invalidated. We can use this freedom to
         // erase by moving towards the end.
         if (b == this->begin() && e != this->end()) {
             this->ptr = e;
         } else {
             const T *const end = this->end();
 
             // move (by assignment) the elements from e to end
             // onto b to the new end
             while (e != end) {
                 *b = std::move(*e);
                 ++b;
                 ++e;
             }
         }
         this->size -= n;
         std::destroy(b, e);
     }
 
     void eraseFirst() noexcept
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(this->size);
         this->begin()->~T();
         ++this->ptr;
         --this->size;
     }
 
     void eraseLast() noexcept
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(this->size);
         (this->end() - 1)->~T();
         --this->size;
     }
 
 
     void assign(T *b, T *e, parameter_type t)
     {
         Q_ASSERT(b <= e);
         Q_ASSERT(b >= this->begin() && e <= this->end());
 
         while (b != e)
             *b++ = t;
     }
 };
 
 template <class T>
 struct QMovableArrayOps
     : QGenericArrayOps<T>
 {
     static_assert (std::is_nothrow_destructible_v<T>, "Types with throwing destructors are not supported in Qt containers.");
 
 protected:
     typedef QTypedArrayData<T> Data;
     using DataPointer = QArrayDataPointer<T>;
 
 public:
     // using QGenericArrayOps<T>::copyAppend;
     // using QGenericArrayOps<T>::moveAppend;
     // using QGenericArrayOps<T>::truncate;
     // using QGenericArrayOps<T>::destroyAll;
     typedef typename QGenericArrayOps<T>::parameter_type parameter_type;
 
     struct Inserter
     {
         QArrayDataPointer<T> * const data;
         T *displaceFrom;
         T * const displaceTo;
         const qsizetype nInserts = 0;
         const size_t bytes;
 
         void verifyPost()
         { Q_ASSERT(displaceFrom == displaceTo); }
 
         explicit Inserter(QArrayDataPointer<T> *d, qsizetype pos, qsizetype n)
             : data{d},
               displaceFrom{d->ptr + pos},
               displaceTo{displaceFrom + n},
               nInserts{n},
               bytes{(data->size - pos) * sizeof(T)}
         {
             ::memmove(static_cast<void *>(displaceTo), static_cast<void *>(displaceFrom), bytes);
         }
         ~Inserter() {
             auto inserts = nInserts;
             if constexpr (!std::is_nothrow_copy_constructible_v<T>) {
                 if (displaceFrom != displaceTo) {
                     ::memmove(static_cast<void *>(displaceFrom), static_cast<void *>(displaceTo), bytes);
                     inserts -= qAbs(displaceFrom - displaceTo);
                 }
             }
             data->size += inserts;
         }
         Q_DISABLE_COPY(Inserter)
 
         void insertRange(const T *source, qsizetype n)
         {
             while (n--) {
                 new (displaceFrom) T(*source);
                 ++source;
                 ++displaceFrom;
             }
             verifyPost();
         }
 
         void insertFill(const T &t, qsizetype n)
         {
             while (n--) {
                 new (displaceFrom) T(t);
                 ++displaceFrom;
             }
             verifyPost();
         }
 
         void insertOne(T &&t)
         {
             new (displaceFrom) T(std::move(t));
             ++displaceFrom;
             verifyPost();
         }
 
     };
 
 
     void insert(qsizetype i, const T *data, qsizetype n)
     {
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         DataPointer oldData;
         this->detachAndGrow(pos, n, &data, &oldData);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         if (growsAtBegin) {
             // copy construct items in reverse order at the begin
             Q_ASSERT(this->freeSpaceAtBegin() >= n);
             while (n) {
                 --n;
                 new (this->begin() - 1) T(data[n]);
                 --this->ptr;
                 ++this->size;
             }
         } else {
             Inserter(this, i, n).insertRange(data, n);
         }
     }
 
     void insert(qsizetype i, qsizetype n, parameter_type t)
     {
         T copy(t);
 
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         this->detachAndGrow(pos, n, nullptr, nullptr);
         Q_ASSERT((pos == Data::GrowsAtBeginning && this->freeSpaceAtBegin() >= n) ||
                  (pos == Data::GrowsAtEnd && this->freeSpaceAtEnd() >= n));
 
         if (growsAtBegin) {
             // copy construct items in reverse order at the begin
             Q_ASSERT(this->freeSpaceAtBegin() >= n);
             while (n--) {
                 new (this->begin() - 1) T(copy);
                 --this->ptr;
                 ++this->size;
             }
         } else {
             Inserter(this, i, n).insertFill(copy, n);
         }
     }
 
     template<typename... Args>
     void emplace(qsizetype i, Args &&... args)
     {
         bool detach = this->needsDetach();
         if (!detach) {
             if (i == this->size && this->freeSpaceAtEnd()) {
                 new (this->end()) T(std::forward<Args>(args)...);
                 ++this->size;
                 return;
             }
             if (i == 0 && this->freeSpaceAtBegin()) {
                 new (this->begin() - 1) T(std::forward<Args>(args)...);
                 --this->ptr;
                 ++this->size;
                 return;
             }
         }
         T tmp(std::forward<Args>(args)...);
         const bool growsAtBegin = this->size != 0 && i == 0;
         const auto pos = growsAtBegin ? Data::GrowsAtBeginning : Data::GrowsAtEnd;
 
         this->detachAndGrow(pos, 1, nullptr, nullptr);
         if (growsAtBegin) {
             Q_ASSERT(this->freeSpaceAtBegin());
             new (this->begin() - 1) T(std::move(tmp));
             --this->ptr;
             ++this->size;
         } else {
             Inserter(this, i, 1).insertOne(std::move(tmp));
         }
     }
 
     void erase(T *b, qsizetype n)
     {
         T *e = b + n;
 
         Q_ASSERT(this->isMutable());
         Q_ASSERT(b < e);
         Q_ASSERT(b >= this->begin() && b < this->end());
         Q_ASSERT(e > this->begin() && e <= this->end());
 
         // Comply with std::vector::erase(): erased elements and all after them
         // are invalidated. However, erasing from the beginning effectively
         // means that all iterators are invalidated. We can use this freedom to
         // erase by moving towards the end.
 
         std::destroy(b, e);
         if (b == this->begin() && e != this->end()) {
             this->ptr = e;
         } else if (e != this->end()) {
             memmove(static_cast<void *>(b), static_cast<const void *>(e), (static_cast<const T *>(this->end()) - e)*sizeof(T));
         }
         this->size -= n;
     }
 
     void reallocate(qsizetype alloc, QArrayData::AllocationOption option)
     {
         auto pair = Data::reallocateUnaligned(this->d, this->ptr, alloc, option);
         Q_CHECK_PTR(pair.second);
         Q_ASSERT(pair.first != nullptr);
         this->d = pair.first;
         this->ptr = pair.second;
     }
 };
 
 template <class T, class = void>
 struct QArrayOpsSelector
 {
     typedef QGenericArrayOps<T> Type;
 };
 
 template <class T>
 struct QArrayOpsSelector<T,
     typename std::enable_if<
         !QTypeInfo<T>::isComplex && QTypeInfo<T>::isRelocatable
     >::type>
 {
     typedef QPodArrayOps<T> Type;
 };
 
 template <class T>
 struct QArrayOpsSelector<T,
     typename std::enable_if<
         QTypeInfo<T>::isComplex && QTypeInfo<T>::isRelocatable
     >::type>
 {
     typedef QMovableArrayOps<T> Type;
 };
 
 template <class T>
 struct QCommonArrayOps : QArrayOpsSelector<T>::Type
 {
     using Base = typename QArrayOpsSelector<T>::Type;
     using Data = QTypedArrayData<T>;
     using DataPointer = QArrayDataPointer<T>;
     using parameter_type = typename Base::parameter_type;
 
 protected:
     using Self = QCommonArrayOps<T>;
 
 public:
     // using Base::truncate;
     // using Base::destroyAll;
 
     template<typename It>
     void appendIteratorRange(It b, It e, QtPrivate::IfIsForwardIterator<It> = true)
     {
         Q_ASSERT(this->isMutable() || b == e);
         Q_ASSERT(!this->isShared() || b == e);
         const qsizetype distance = std::distance(b, e);
         Q_ASSERT(distance >= 0 && distance <= this->allocatedCapacity() - this->size);
         Q_UNUSED(distance);
 
 #if __cplusplus >= 202002L && defined(__cpp_concepts) && defined(__cpp_lib_concepts)
         constexpr bool canUseCopyAppend =
                 std::contiguous_iterator<It> &&
                 std::is_same_v<
                     std::remove_cv_t<typename std::iterator_traits<It>::value_type>,
                     T
                 >;
         if constexpr (canUseCopyAppend) {
             this->copyAppend(std::to_address(b), std::to_address(e));
         } else
 #endif
         {
             T *iter = this->end();
             for (; b != e; ++iter, ++b) {
                 new (iter) T(*b);
                 ++this->size;
             }
         }
     }
 
     // slightly higher level API than copyAppend() that also preallocates space
     void growAppend(const T *b, const T *e)
     {
         if (b == e)
             return;
         Q_ASSERT(b < e);
         const qsizetype n = e - b;
         DataPointer old;
 
         // points into range:
         if (QtPrivate::q_points_into_range(b, *this))
             this->detachAndGrow(QArrayData::GrowsAtEnd, n, &b, &old);
         else
             this->detachAndGrow(QArrayData::GrowsAtEnd, n, nullptr, nullptr);
         Q_ASSERT(this->freeSpaceAtEnd() >= n);
         // b might be updated so use [b, n)
         this->copyAppend(b, b + n);
     }
 
     void appendUninitialized(qsizetype newSize)
     {
         Q_ASSERT(this->isMutable());
         Q_ASSERT(!this->isShared());
         Q_ASSERT(newSize > this->size);
         Q_ASSERT(newSize - this->size <= this->freeSpaceAtEnd());
 
 
         T *const b = this->begin() + this->size;
         T *const e = this->begin() + newSize;
         if constexpr (std::is_constructible_v<T, Qt::Initialization>)
             std::uninitialized_fill(b, e, Qt::Uninitialized);
         else
             std::uninitialized_default_construct(b, e);
         this->size = newSize;
     }
 
     using Base::assign;
 
     template <typename InputIterator, typename Projection = q20::identity>
     void assign(InputIterator first, InputIterator last, Projection proj = {})
     {
         // This function only provides the basic exception guarantee.
         using Category = typename std::iterator_traits<InputIterator>::iterator_category;
         constexpr bool IsFwdIt = std::is_convertible_v<Category, std::forward_iterator_tag>;
 
         const qsizetype n = IsFwdIt ? std::distance(first, last) : 0;
         bool undoPrependOptimization = true;
         bool needCapacity = n > this->constAllocatedCapacity();
         if (needCapacity || this->needsDetach()) {
             qsizetype newCapacity = this->detachCapacity(n);
             bool wasLastRef = !this->deref();
             if (wasLastRef && needCapacity) {
                 // free memory we can't reuse
                 this->destroyAll();
                 Data::deallocate(this->d);
             }
             if (!needCapacity && wasLastRef) {
                 // we were the last reference and can reuse the storage
                 this->d->ref_.storeRelaxed(1);
             } else {
                 // we must allocate new memory
                 std::tie(this->d, this->ptr) = Data::allocate(newCapacity);
                 this->size = 0;
                 undoPrependOptimization = false;
             }
         }
 
         if constexpr (!std::is_nothrow_constructible_v<T, decltype(std::invoke(proj, *first))>
                       || !std::is_nothrow_invocable_v<Projection, decltype(*first)>)
         {
             // If construction can throw, and we have freeSpaceAtBegin(),
             // it's easiest to just clear the container and start fresh.
             // The alternative would be to keep track of two active, disjoint ranges.
             if (undoPrependOptimization) {
                 this->truncate(0);
                 this->setBegin(Data::dataStart(this->d, alignof(typename Data::AlignmentDummy)));
                 undoPrependOptimization = false;
             }
         }
 
         const auto dend = this->end();
         T *dst = this->begin();
         T *capacityBegin = dst;
         if (undoPrependOptimization) {
             capacityBegin = Data::dataStart(this->d, alignof(typename Data::AlignmentDummy));
             this->setBegin(capacityBegin); // undo prepend optimization
         }
 
         assign_impl(first, last, capacityBegin, dst, dend, proj, Category{});
     }
 
     template <typename InputIterator, typename Projection>
     void assign_impl(InputIterator first, InputIterator last, T *capacityBegin, T *dst, T *dend,
                      Projection proj, std::input_iterator_tag)
     {
         if (qsizetype offset = dst - capacityBegin) {
             T *prependBufferEnd = dst;
             dst = capacityBegin;
 
             // By construction, the following loop is nothrow!
             // (otherwise, we can't reach here)
             // Assumes InputIterator operations don't throw.
             // (but we can't statically assert that, as these operations
             //  have preconditons, so typically aren't noexcept)
             while (true) {
                 if (dst == prependBufferEnd) {  // ran out of prepend buffer space
                     this->size += offset;
                     // we now have a contiguous buffer, continue with the main loop:
                     break;
                 }
                 if (first == last) {            // ran out of elements to assign
                     std::destroy(prependBufferEnd, dend);
                     this->size = dst - this->begin();
                     return;
                 }
                 // construct element in prepend buffer
                 q20::construct_at(dst, std::invoke(proj, *first));
                 ++dst;
                 ++first;
             }
         }
         while (true) {
             if (first == last) {    // ran out of elements to assign
                 std::destroy(dst, dend);
                 break;
             }
             if (dst == dend) {      // ran out of existing elements to overwrite
                 do {
                     this->emplace(this->size, std::invoke(proj, *first));
                 } while (++first != last);
                 return;         // size() is already correct (and dst invalidated)!
             }
             *dst = std::invoke(proj, *first);    // overwrite existing element
             ++dst;
             ++first;
         }
         this->size = dst - this->begin();
     }
 
     template <typename InputIterator, typename Projection>
     void assign_impl(InputIterator first, InputIterator last, T *capacityBegin, T *dst, T *dend,
                      Projection proj, std::forward_iterator_tag)
     {
         constexpr bool IsIdentity = std::is_same_v<Projection, q20::identity>;
         const qsizetype n = std::distance(first, last);
         if constexpr (IsIdentity && !QTypeInfo<T>::isComplex) {
             // For non-complex types, we prefer a single std::copy() -> memcpy()
             // call. We can do that because either the default constructor is
             // trivial (so the lifetime has started) or the copy constructor is
             // (and won't care what the stored value is).
             std::copy(first, last, capacityBegin);
         } else {
             // There are two possibilities:
             // 1) fewer elements than the current allocated space
             //    | prepend buffer | array |  destroy  |
             // 2) more elements than the current allocated space
             //    | prepend buffer | array | construct |
             //
             // Both the prepend buffer and the current array may be empty.
 
             // construct elements in the prepend buffer
             while (first != last && capacityBegin != dst) {
                 q20::construct_at(capacityBegin, std::invoke(proj, *first));
                 ++first;
                 ++capacityBegin;
             }
 
             // overwrite elements in the existing array
             while (first != last && dst != dend) {
                 *dst = std::invoke(proj, *first);    // overwrite existing element
                 ++first;
                 ++dst;
             }
 
             // construct new elements in the append buffer
             while (first != last) {
                 q20::construct_at(dst, std::invoke(proj, *first));
                 ++first;
                 ++dst;
             }
             // or destroy elements from the existing array
             if (dst < dend)
                 std::destroy(dst, dend);
         }
         this->size = n;
     }
 };
 
 } // namespace QtPrivate
 
 template <class T>
 struct QArrayDataOps
     : QtPrivate::QCommonArrayOps<T>
 {
 };
 
 QT_END_NAMESPACE
 
 #endif // include guard

This page was automatically generated by the 2.3.7 LXR engine. The LXR team