[Development] Help needed: MSVC 2017 compiler bug with QHash in 5.15 - QTBUG-82166

[Thiago Macieira]

https://bugreports.qt.io/browse/QTBUG-82166

The bug report says:
qmap.h(1213): error C2244: "QMultiMap<K,V>::insert": Keine Übereinstimmung für 
Funktionsdefinition mit vorhandener Deklaration gefunden [...
\msvc.build_x64\audiofile\audiofile.vcxproj]
qmap.h(1211): note: Siehe Deklaration von "QMultiMap<K,V>::insert"
qmap.h(1213): note: Definition
qmap.h(1213): note: 'QMultiMap<K,V>::iterator QMultiMap<K,V>::insert(const Key 
&,const T &)'
qmap.h(1213): note: Vorhandene Deklarationen
qmap.h(1213): note: 'QMap<K,V>::iterator 
QMultiMap<K,V>::insert(QMap<K,V>::const_iterator,const Key &,const T &)'
qmap.h(1213): note: 'QMap<K,V>::iterator QMultiMap<K,V>::insert(const Key 
&,const T &)'

my sloppy translation of German is that the compiler is at the definition of 
QMultiMap<K,V>::iterator QMultiMap<K,V>::insert(const Key &,const T &)

and can't find the previous declaration of such a function. It suggests these 
two instead:
QMap<K,V>::iterator QMultiMap<K,V>::insert(QMap<K,V>::const_iterator,const Key 
&,const T &)
QMap<K,V>::iterator QMultiMap<K,V>::insert(const Key &,const T &)

The second one should have matched, since QMultiMap's iterator is just QMap's:
    using typename QMap<Key, T>::iterator;

In fact, this is a using declaration, not a typedef.

MSVC 2019 compiled the change without a problem and the CI seems to have found 
no problem. The bug reporter indicates this is happening on a precompiled 
header, so it may be difficult to reproduce.

Is there a volunteer to help figuring this out? I'm strapped for time and 
access to the 2017 compiler is limited for me.
-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel System Software Products