1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

QList: properly declare operator== for MSVC

Browse Source 
The operators were declared as friend function templates (so, free
functions in the Qt namespace). Unfortunately, the template argument
of the operators was also defaulted -- causing MSVC trying to
instantiate those functions at all times, causing interesting
recursive template instantiation errors (C2968). It's extremely
likely that we're facing a MSVC bug, but work around it by not
defaulting the template argument. This in turn requires to move
the function definition outside QList's definition, otherwise
an extern template definition (like the ones we have for QList<QPoint>)
would cause a template redefinition error...

Change-Id: If03477ac1fa0a72aa252bb9e08e2a19c2b517b1b
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This commit is contained in:
Giuseppe D'Angelo 2020-08-03 16:42:30 +02:00
parent 8003ae79bf
commit 31c232d3b7
1 changed files with 22 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
src/corelib/tools/qlist.h
View File

@ -162,22 +162,10 @@ public:
void swap(QList<T> &other) noexcept { qSwap(d, other.d); }
template <typename U = T>
friend QTypeTraits::compare_eq_result<U> operator==(const QList &l, const QList &r)
{
if (l.size() != r.size())
return false;
if (l.begin() == r.begin())
return true;
// do element-by-element comparison
return l.d->compare(l.begin(), r.begin(), l.size());
}
template <typename U = T>
friend QTypeTraits::compare_eq_result<U> operator!=(const QList &l, const QList &r)
{
return !(l == r);
}
template <typename U>
friend QTypeTraits::compare_eq_result<U> operator==(const QList<U> &l, const QList<U> &r);
template <typename U>
friend QTypeTraits::compare_eq_result<U> operator!=(const QList<U> &l, const QList<U> &r);
qsizetype size() const noexcept { return d->size; }
qsizetype count() const noexcept { return size(); }
@ -792,6 +780,24 @@ size_t qHash(const QList<T> &key, size_t seed = 0)
return qHashRange(key.cbegin(), key.cend(), seed);
}
template <typename U>
QTypeTraits::compare_eq_result<U> operator==(const QList<U> &l, const QList<U> &r)
{
if (l.size() != r.size())
return false;
if (l.begin() == r.begin())
return true;
// do element-by-element comparison
return l.d->compare(l.begin(), r.begin(), l.size());
}
template <typename U>
QTypeTraits::compare_eq_result<U> operator!=(const QList<U> &l, const QList<U> &r)
{
return !(l == r);
}
template <typename T>
auto operator<(const QList<T> &lhs, const QList<T> &rhs)
noexcept(noexcept(std::lexicographical_compare(lhs.begin(), lhs.end(),