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// Copyright (C) 2020 The Qt Company Ltd.
// Copyright (C) 2019 Intel Corporation.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef QFOREACH_H
#define QFOREACH_H
#include <QtCore/qglobal.h>
QT_BEGIN_NAMESPACE
#if 0
#pragma qt_class(QForeach)
#pragma qt_sync_stop_processing
#endif
#ifndef QT_NO_FOREACH
namespace QtPrivate {
template <typename T>
class QForeachContainer {
Q_DISABLE_COPY(QForeachContainer)
public:
QForeachContainer(const T &t) : c(t), i(qAsConst(c).begin()), e(qAsConst(c).end()) {}
QForeachContainer(T &&t) : c(std::move(t)), i(qAsConst(c).begin()), e(qAsConst(c).end()) {}
QForeachContainer(QForeachContainer &&other)
: c(std::move(other.c)),
i(qAsConst(c).begin()),
e(qAsConst(c).end()),
control(std::move(other.control))
{
}
QForeachContainer &operator=(QForeachContainer &&other)
{
c = std::move(other.c);
i = qAsConst(c).begin();
e = qAsConst(c).end();
control = std::move(other.control);
return *this;
}
T c;
typename T::const_iterator i, e;
int control = 1;
};
// Containers that have a detach function are considered shared, and are OK in a foreach loop
template <typename T, typename = decltype(std::declval<T>().detach())>
inline void warnIfContainerIsNotShared(int) {}
#if QT_DEPRECATED_SINCE(6, 0)
// Other containers will copy themselves if used in foreach, this use is deprecated
template <typename T>
QT_DEPRECATED_VERSION_X_6_0("Do not use foreach/Q_FOREACH with containers which are not implicitly shared. "
"Prefer using a range-based for loop with these containers: `for (const auto &it : container)`, "
"keeping in mind that range-based for doesn't copy the container as Q_FOREACH does")
inline void warnIfContainerIsNotShared(...) {}
#endif
template<typename T>
QForeachContainer<typename std::decay<T>::type> qMakeForeachContainer(T &&t)
{
warnIfContainerIsNotShared<typename std::decay<T>::type>(0);
return QForeachContainer<typename std::decay<T>::type>(std::forward<T>(t));
}
}
// Use C++17 if statement with initializer. User's code ends up in a else so
// scoping of different ifs is not broken
#define Q_FOREACH_IMPL(variable, name, container) \
for (auto name = QtPrivate::qMakeForeachContainer(container); name.i != name.e; ++name.i) \
if (variable = *name.i; false) {} else
#define Q_FOREACH_JOIN(A, B) Q_FOREACH_JOIN_IMPL(A, B)
#define Q_FOREACH_JOIN_IMPL(A, B) A ## B
#define Q_FOREACH(variable, container) \
Q_FOREACH_IMPL(variable, Q_FOREACH_JOIN(_container_, __LINE__), container)
#endif // QT_NO_FOREACH
#define Q_FOREVER for(;;)
#ifndef QT_NO_KEYWORDS
# ifndef QT_NO_FOREACH
# ifndef foreach
# define foreach Q_FOREACH
# endif
# endif // QT_NO_FOREACH
# ifndef forever
# define forever Q_FOREVER
# endif
#endif
QT_END_NAMESPACE
#endif /* QFOREACH_H */
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