Introduce QByteArrayView

Created a QByteArrayView in symmetry with QStringView.
Added the basic tests symmetrical to QStringView tests.

Moved the implementations of non-modifying methods of QByteArray to
namespace QtPrivate, to be reused inline from both QByteArray and
QByteArrayView. Changed QByteArray's counterparts of those methods to
take QByteArrayView as argument instead of QByteArray. Removed
QByteArray's operator QNoImplicitBoolCast(), because it was causing
ambiguity when calling those methods with QByteArray argument (it was
there to perevnt if(!ba)/if(ba) from compiling, but currently that would
be ambiguous and won't compile anyway).

[ChangeLog][QtCore][QByteArrayView] New class.

Task-number: QTBUG-84321
Change-Id: I05f92e654cf65c95f2bb31b9c9018746ac110426
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 76 insertions, 0 deletions

diff --git a/src/corelib/text/qbytearrayalgorithms.h b/src/corelib/text/qbytearrayalgorithms.h
new file mode 100644
index 0000000000..fdcd00a8c1
--- /dev/null
+++ b/src/corelib/text/qbytearrayalgorithms.h
@@ -0,0 +1,76 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://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 QBYTEARRAYALGORITHMS_H
+#define QBYTEARRAYALGORITHMS_H
+
+#include <QtCore/qnamespace.h>
+
+#if 0
+#pragma qt_class(QByteArrayAlgorithms)
+#endif
+
+QT_BEGIN_NAMESPACE
+
+class QByteArrayView;
+
+namespace QtPrivate {
+
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION
+bool startsWith(QByteArrayView haystack, QByteArrayView needle) noexcept;
+
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION
+bool endsWith(QByteArrayView haystack, QByteArrayView needle) noexcept;
+
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION
+qsizetype findByteArray(QByteArrayView haystack, qsizetype from, QByteArrayView needle) noexcept;
+
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION
+qsizetype lastIndexOf(QByteArrayView haystack, qsizetype from, QByteArrayView needle) noexcept;
+
+[[nodiscard]] Q_CORE_EXPORT Q_DECL_PURE_FUNCTION
+qsizetype count(QByteArrayView haystack, QByteArrayView needle) noexcept;
+
+[[nodiscard]] Q_CORE_EXPORT int compareMemory(QByteArrayView lhs, QByteArrayView rhs);
+
+} // namespace QtPrivate
+
+QT_END_NAMESPACE
+
+#endif // QBYTEARRAYALGORITHMS_H