I have some code which boils down to this:
#include <QVector>
void test()
{
struct S
{
const QVector<int> v; // compiles if not const
};
QVector<std::pair<S, S>> pv; // doesn't compile with this
//std::vector<std::pair<S, S>> pv; // compiles with this
pv.push_back(std::make_pair<S, S>({}, {}));
}
This compiles in Qt 5.15.12, but not in 6.4.2.
The last line generates no less than 4 errors, resulting in pages and
pages of output, but essentially:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:472:29: error: use of deleted function
‘std::pair<test()::S, test()::S>& std::pair<test()::S, test()::S>::operator=(const
std::pair<test()::S, test()::S>&)’
472 | last[i] = std::move(last[i - 1]);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
--
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:475:24: error: use of deleted function
‘std::pair<test()::S, test()::S>& std::pair<test()::S, test()::S>::operator=(const
std::pair<test()::S, test()::S>&)’
475 | *where = std::move(t);
| ~~~~~~~^~~~~~~~~~~~~~
--
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:132:18: error: use of deleted
function ‘std::pair<test()::S, test()::S>& std::pair<test()::S,
test()::S>::operator=(const std::pair<test()::S, test()::S>&)’
132 | *d_first = std::move_if_noexcept(*first);
| ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:132:18: error: use of deleted
function ‘std::pair<test()::S, test()::S>& std::pair<test()::S,
test()::S>::operator=(const std::pair<test()::S, test()::S>&)’
As per the comments, it compiles if the member variable in the inner
struct is not const, or if I use a std::vector instead of QVector.
Is there a solution?
Full error text below.
Hamish
In file included from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:8,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qvector.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/QVector:1,
from test.cc:1:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h: In instantiation of ‘void
QtPrivate::QGenericArrayOps<T>::Inserter::insertOne(qsizetype, T&&) [with T =
std::pair<test()::S, test()::S>; qsizetype = long long int]’:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:557:37: required from ‘void
QtPrivate::QGenericArrayOps<T>::emplace(qsizetype, Args&& ...) [with Args =
{std::pair<test()::S, test()::S>}; T = std::pair<test()::S, test()::S>; qsizetype = long long
int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:852:15: required from ‘T&
QList<T>::emplaceBack(Args&& ...) [with Args = {std::pair<test()::S, test()::S>}; T =
std::pair<test()::S, test()::S>; QList<T>::reference = std::pair<test()::S, test()::S>&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:440:24: required from ‘void
QList<T>::append(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:652:42: required from ‘void
QList<T>::push_back(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
test.cc:13:43: required from here
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:472:29: error: use of deleted function
‘std::pair<test()::S, test()::S>& std::pair<test()::S, test()::S>::operator=(const
std::pair<test()::S, test()::S>&)’
472 | last[i] = std::move(last[i - 1]);
| ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/10/utility:70,
from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qglobal.h:11,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qpair.h:7,
from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydata.h:8,
from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:8,
from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:8,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qvector.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/QVector:1,
from test.cc:1:
/usr/include/c++/10/bits/stl_pair.h:211:12: note: ‘std::pair<test()::S, test()::S>&
std::pair<test()::S, test()::S>::operator=(const std::pair<test()::S, test()::S>&)’ is
implicitly declared as deleted because ‘std::pair<test()::S, test()::S>’ declares a move constructor or
move assignment operator
211 | struct pair
| ^~~~
In file included from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:8,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qvector.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/QVector:1,
from test.cc:1:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:475:24: error: use of deleted function
‘std::pair<test()::S, test()::S>& std::pair<test()::S, test()::S>::operator=(const
std::pair<test()::S, test()::S>&)’
475 | *where = std::move(t);
| ~~~~~~~^~~~~~~~~~~~~~
In file included from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:9,
from
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:8,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qvector.h:7,
from ../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/QVector:1,
from test.cc:1:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h: In
instantiation of ‘void QtPrivate::q_relocate_overlap_n_left_move(iterator, N,
iterator) [with iterator = std::pair<test()::S, test()::S>*; N = long long
int]’:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:167:43:
required from ‘void QtPrivate::q_relocate_overlap_n(T*, N, T*) [with T =
std::pair<test()::S, test()::S>; N = long long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:301:40: required from
‘void QArrayDataPointer<T>::relocate(qsizetype, const T**) [with T =
std::pair<test()::S, test()::S>; qsizetype = long long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:286:9: required from
‘bool QArrayDataPointer<T>::tryReadjustFreeSpace(QArrayData::GrowthPosition,
qsizetype, const T**) [with T = std::pair<test()::S, test()::S>; qsizetype = long
long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:187:26: required from ‘void
QArrayDataPointer<T>::detachAndGrow(QArrayData::GrowthPosition, qsizetype, const T**,
QArrayDataPointer<T>*) [with T = std::pair<test()::S, test()::S>; qsizetype = long
long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:549:28: required from ‘void
QtPrivate::QGenericArrayOps<T>::emplace(qsizetype, Args&& ...) [with Args =
{std::pair<test()::S, test()::S>}; T = std::pair<test()::S, test()::S>; qsizetype = long long
int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:852:15: required from ‘T&
QList<T>::emplaceBack(Args&& ...) [with Args = {std::pair<test()::S, test()::S>}; T =
std::pair<test()::S, test()::S>; QList<T>::reference = std::pair<test()::S, test()::S>&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:440:24: required from ‘void
QList<T>::append(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:652:42: required from ‘void
QList<T>::push_back(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
test.cc:13:43: required from here
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:132:18: error: use of deleted
function ‘std::pair<test()::S, test()::S>& std::pair<test()::S,
test()::S>::operator=(const std::pair<test()::S, test()::S>&)’
132 | *d_first = std::move_if_noexcept(*first);
| ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h: In instantiation of
‘void QtPrivate::q_relocate_overlap_n_left_move(iterator, N, iterator) [with iterator =
std::reverse_iterator<std::pair<test()::S, test()::S>*>; N = long long int]’:
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:171:43:
required from ‘void QtPrivate::q_relocate_overlap_n(T*, N, T*) [with T =
std::pair<test()::S, test()::S>; N = long long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:301:40: required from
‘void QArrayDataPointer<T>::relocate(qsizetype, const T**) [with T =
std::pair<test()::S, test()::S>; qsizetype = long long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:286:9: required from
‘bool QArrayDataPointer<T>::tryReadjustFreeSpace(QArrayData::GrowthPosition,
qsizetype, const T**) [with T = std::pair<test()::S, test()::S>; qsizetype = long
long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydatapointer.h:187:26: required from ‘void
QArrayDataPointer<T>::detachAndGrow(QArrayData::GrowthPosition, qsizetype, const T**,
QArrayDataPointer<T>*) [with T = std::pair<test()::S, test()::S>; qsizetype = long
long int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qarraydataops.h:549:28: required from ‘void
QtPrivate::QGenericArrayOps<T>::emplace(qsizetype, Args&& ...) [with Args =
{std::pair<test()::S, test()::S>}; T = std::pair<test()::S, test()::S>; qsizetype = long long
int]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:852:15: required from ‘T&
QList<T>::emplaceBack(Args&& ...) [with Args = {std::pair<test()::S, test()::S>}; T =
std::pair<test()::S, test()::S>; QList<T>::reference = std::pair<test()::S, test()::S>&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:440:24: required from ‘void
QList<T>::append(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qlist.h:652:42: required from ‘void
QList<T>::push_back(QList<T>::rvalue_ref) [with T = std::pair<test()::S, test()::S>;
QList<T>::rvalue_ref = std::pair<test()::S, test()::S>&&]’
test.cc:13:43: required from here
../../dev/Qt6.4.2/6.4.2/gcc_64/include/QtCore/qcontainertools_impl.h:132:18: error: use of deleted
function ‘std::pair<test()::S, test()::S>& std::pair<test()::S,
test()::S>::operator=(const std::pair<test()::S, test()::S>&)’
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