Add private qt_make_unique as a drop-in for C++14 std::make_unique

The original is much more subtle, so don't try to be a 100%
replacement. Most users will be able to use std::make_unique these
days. This is just a minimal implementation to enable using the
functionality in the implementation of Qt libraries. In particular,
it does not attempt to deal with arrays.

It is therefore not proposed as public API. It is placed in a new
private header, since the only header in QtCore that already
includes <memory> is sharedpointer_impl.h, and that did not seem
to be a good place to add it. It is probably too much of a
compilation-time drain to add <memory> to qglobal.h...

Change-Id: Ie206ef7ae9beb36c63aef4ec46dbde6c73e0d9f5
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
 
 
 
 
 
 
 

2 files changed, 72 insertions, 0 deletions

diff --git a/src/corelib/global/global.pri b/src/corelib/global/global.pri
index 428c674307..10af46b41a 100644
--- a/src/corelib/global/global.pri
+++ b/src/corelib/global/global.pri
@@ -7,6 +7,7 @@ HEADERS +=  \
         global/qsystemdetection.h \
         global/qcompilerdetection.h \
         global/qprocessordetection.h \
+        global/qmemory_p.h \
 	global/qnamespace.h \
         global/qendian.h \
         global/qendian_p.h \
diff --git a/src/corelib/global/qmemory_p.h b/src/corelib/global/qmemory_p.h
new file mode 100644
index 0000000000..ac791385bd
--- /dev/null
+++ b/src/corelib/global/qmemory_p.h
@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef QMEMORY_P_H
+#define QMEMORY_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+QT_BEGIN_NAMESPACE
+
+// Like std::make_unique, but less ambitious, so keep as private API, for use in Qt itself:
+template <typename T, typename... Args>
+typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
+qt_make_unique(Args &&...args)
+{
+    return std::unique_ptr<T>{new T(std::forward<Args>(args)...)};
+}
+
+QT_END_NAMESPACE
+
+#endif /* QMEMORY_P_H */