error: C2039: 'pointer' : is not a member of 'QJsonObject::iterator' - c++

Question

I'm having a weird error when trying to use 'QJsonObject::iterator' with MSVC2013.
I have the following example:
#include <QCoreApplication>
#include <QJsonObject>
#include <QDebug>
#include <algorithm>
void processValue(QJsonValue value) {
qDebug() << value.toString();
}
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QJsonObject jsonObject;
jsonObject.insert("a", "A");
jsonObject.insert("b", "B");
jsonObject.insert("c", "C");
jsonObject.insert("d", "D");
jsonObject.insert("e", "E");
std::for_each (jsonObject.begin(), jsonObject.end(), processValue);
return a.exec();
}
This code compiles and works as expected with MSVC2008 (cross-compiling to WinCE) and MinGW, but not with MSVC2013. In all cases, I'm using Qt 5.5.1.
The error message is:
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : error C2039: 'pointer' : is not a member of 'QJsonObject::iterator'
c:\qt\qt5.5.1msvc\5.5\msvc2013\include\qtcore\qjsonobject.h(96) : see declaration of 'QJsonObject::iterator'
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(584) : see reference to class template instantiation 'std::iterator_traits<_InIt>' being compiled
with
[
_InIt=QJsonObject::iterator
]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\algorithm(31) : see reference to function template instantiation 'void std::_Debug_range<_InIt>(_InIt,_InIt,std::_Dbfile_t,std::_Dbline_t)' being compiled
with
[
_InIt=QJsonObject::iterator
]
..\QJsonObjectIteratorIssue\main.cpp(21) : see reference to function template instantiation '_Fn1 std::for_each<QJsonObject::iterator,void(__cdecl *)(QJsonValue)>(_InIt,_InIt,_Fn1)' being compiled
with
[
_Fn1=void (__cdecl *)(QJsonValue)
, _InIt=QJsonObject::iterator
]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : error C2146: syntax error : missing ';' before identifier 'pointer'
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : error C2602: 'std::iterator_traits<_InIt>::pointer' is not a member of a base class of 'std::iterator_traits<_InIt>'
with
[
_InIt=QJsonObject::iterator
]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : see declaration of 'std::iterator_traits<_InIt>::pointer'
with
[
_InIt=QJsonObject::iterator
]
C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\INCLUDE\xutility(375) : error C2868: 'std::iterator_traits<_InIt>::pointer' : illegal syntax for using-declaration; expected qualified-name
with
[
_InIt=QJsonObject::iterator
]
Am I doing anything wrong here, that just happen to work by chance on the 2 other compilers?

Answer 1

Use 5.6 or backport this: https://code.qt.io/cgit/qt/qtbase.git/commit/?id=4a318a61824216ac499ff8b0b0c55dea90501005
QJsonObject::(const_)iterator: add pointer typedef
Otherwise they're unusable with std::algorithms or anything else
that requires iterator_traits.