Deprecate QScopedPointer::take()

We've decided that QScopedPointer shouldn't be movable,
because it would break the semantics of being "scoped"
(the pointer/pointee won't survive the scope).

Then, QScopedPointer shouldn't allow for take() either.
If you need those semantics, reach for unique_ptr.

[ChangeLog][QtCore][QScopedPointer] The take() function
has been deprecated. This was an API mistake, as it
allowed the pointer/pointee to escape from the scope,
defeating the point of the QScopedPointer class. If you
need such semantics, use std::unique_ptr (and call
release()).

Change-Id: I3236f085f763b04eb98e3242abc06f7c54fb3d8b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

5 files changed, 16 insertions, 9 deletions

diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index 16fd09efdb..9dd0f4ac1d 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -63,6 +63,7 @@
 #endif
 
 #include <algorithm>
+#include <memory>
 #include <stdlib.h>
 
 QT_BEGIN_NAMESPACE
@@ -1022,12 +1023,12 @@ bool QDir::cd(const QString &dirName)
         }
     }
 
-    QScopedPointer<QDirPrivate> dir(new QDirPrivate(*d_ptr.constData()));
+    std::unique_ptr<QDirPrivate> dir(new QDirPrivate(*d_ptr.constData()));
     dir->setPath(newPath);
     if (!dir->exists())
         return false;
 
-    d_ptr = dir.take();
+    d_ptr = dir.release();
     return true;
 }
 
@@ -1730,7 +1731,7 @@ bool QDir::isRelative() const
 bool QDir::makeAbsolute()
 {
     const QDirPrivate *d = d_ptr.constData();
-    QScopedPointer<QDirPrivate> dir;
+    std::unique_ptr<QDirPrivate> dir;
     if (!!d->fileEngine) {
         QString absolutePath = d->fileEngine->fileName(QAbstractFileEngine::AbsoluteName);
         if (QDir::isRelativePath(absolutePath))
@@ -1743,7 +1744,7 @@ bool QDir::makeAbsolute()
         dir.reset(new QDirPrivate(*d_ptr.constData()));
         dir->setPath(d->absoluteDirEntry.filePath());
     }
-    d_ptr = dir.take(); // actually detach
+    d_ptr = dir.release(); // actually detach
     return true;
 }
 
diff --git a/src/corelib/tools/qscopedpointer.cpp b/src/corelib/tools/qscopedpointer.cpp
index b067392071..1dd77a22dc 100644
--- a/src/corelib/tools/qscopedpointer.cpp
+++ b/src/corelib/tools/qscopedpointer.cpp
@@ -251,6 +251,8 @@ QT_BEGIN_NAMESPACE
 /*!
     \fn template <typename T, typename Cleanup> T *QScopedPointer<T, Cleanup>::take()
 
+    \obsolete Use std::unique_ptr and release() instead.
+
     Returns the value of the pointer referenced by this object. The pointer of this
     QScopedPointer object will be reset to \nullptr.
 
diff --git a/src/corelib/tools/qscopedpointer.h b/src/corelib/tools/qscopedpointer.h
index 5b2a15f5f6..2297d7cb1e 100644
--- a/src/corelib/tools/qscopedpointer.h
+++ b/src/corelib/tools/qscopedpointer.h
@@ -151,12 +151,15 @@ public:
         Cleanup::cleanup(oldD);
     }
 
+#if QT_DEPRECATED_SINCE(6, 1)
+    QT_DEPRECATED_VERSION_X_6_1("Use std::unique_ptr instead, and call release().")
     T *take() noexcept
     {
         T *oldD = d;
         d = nullptr;
         return oldD;
     }
+#endif
 
     void swap(QScopedPointer<T, Cleanup> &other) noexcept
     {
diff --git a/src/dbus/qdbusdemarshaller.cpp b/src/dbus/qdbusdemarshaller.cpp
index c9da593ad2..39d2dd0354 100644
--- a/src/dbus/qdbusdemarshaller.cpp
+++ b/src/dbus/qdbusdemarshaller.cpp
@@ -40,7 +40,7 @@
 #include "qdbusargument_p.h"
 #include "qdbusconnection.h"
 
-#include <qscopedpointer.h>
+#include <memory>
 
 #include <stdlib.h>
 
@@ -426,12 +426,12 @@ QDBusDemarshaller *QDBusDemarshaller::endCommon()
 
 QDBusArgument QDBusDemarshaller::duplicate()
 {
-    QScopedPointer<QDBusDemarshaller> d(new QDBusDemarshaller(capabilities));
+    std::unique_ptr<QDBusDemarshaller> d(new QDBusDemarshaller(capabilities));
     d->iterator = iterator;
     d->message = q_dbus_message_ref(message);
 
     q_dbus_message_iter_next(&iterator);
-    return QDBusArgumentPrivate::create(d.take());
+    return QDBusArgumentPrivate::create(d.release());
 }
 
 QT_END_NAMESPACE
diff --git a/src/xml/dom/qdom.cpp b/src/xml/dom/qdom.cpp
index 585e6875e2..b7c676dd09 100644
--- a/src/xml/dom/qdom.cpp
+++ b/src/xml/dom/qdom.cpp
@@ -62,6 +62,7 @@
 
 #include <stdio.h>
 #include <limits>
+#include <memory>
 
 QT_BEGIN_NAMESPACE
 
@@ -2554,7 +2555,7 @@ QDomNamedNodeMapPrivate::~QDomNamedNodeMapPrivate()
 
 QDomNamedNodeMapPrivate* QDomNamedNodeMapPrivate::clone(QDomNodePrivate* p)
 {
-    QScopedPointer<QDomNamedNodeMapPrivate> m(new QDomNamedNodeMapPrivate(p));
+    std::unique_ptr<QDomNamedNodeMapPrivate> m(new QDomNamedNodeMapPrivate(p));
     m->readonly = readonly;
     m->appendToParent = appendToParent;
 
@@ -2567,7 +2568,7 @@ QDomNamedNodeMapPrivate* QDomNamedNodeMapPrivate::clone(QDomNodePrivate* p)
 
     // we are no longer interested in ownership
     m->ref.deref();
-    return m.take();
+    return m.release();
 }
 
 void QDomNamedNodeMapPrivate::clearMap()