1 files changed, 96 insertions, 0 deletions
diff --git a/src/multimedia/qmaybe_p.h b/src/multimedia/qmaybe_p.h
new file mode 100644
index 000000000..5fe2d4d6c
--- /dev/null
+++ b/src/multimedia/qmaybe_p.h
@@ -0,0 +1,96 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#ifndef QMAYBE_P_H
+#define QMAYBE_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/private/qglobal_p.h>
+#include <qstring.h>
+#include <optional>
+#include <utility>
+#include <memory>
+
+QT_BEGIN_NAMESPACE
+
+struct QUnexpect
+{
+};
+
+static constexpr QUnexpect unexpect{};
+
+template <typename Value, typename Error = QString>
+class QMaybe
+{
+public:
+    QMaybe(const Value &v)
+    {
+        if constexpr (std::is_pointer_v<Value>) {
+            if (!v)
+                return; // nullptr is treated as nullopt (for raw pointer types only)
+        }
+        m_value = v;
+    }
+
+    QMaybe(Value &&v)
+    {
+        if constexpr (std::is_pointer_v<Value>) {
+            if (!v)
+                return; // nullptr is treated as nullopt (for raw pointer types only)
+        }
+        m_value = std::move(v);
+    }
+
+    QMaybe(const QMaybe &other) = default;
+
+    QMaybe &operator=(const QMaybe &other) = default;
+
+    QMaybe(const Error &error) : m_error(error) { }
+
+    template <class... Args>
+    QMaybe(QUnexpect, Args &&...args) : m_error{ std::forward<Args>(args)... }
+    {
+        static_assert(std::is_constructible_v<Error, Args &&...>,
+                      "Invalid arguments for creating an error type");
+    }
+
+    constexpr explicit operator bool() const noexcept { return m_value.has_value(); }
+
+    constexpr Value &value()
+    {
+        Q_ASSERT(m_value.has_value());
+        return *m_value;
+    }
+
+    constexpr const Value &value() const
+    {
+        Q_ASSERT(m_value.has_value());
+        return *m_value;
+    }
+
+    constexpr Value *operator->() noexcept { return std::addressof(value()); }
+    constexpr const Value *operator->() const noexcept { return std::addressof(value()); }
+
+    constexpr Value &operator*() &noexcept { return value(); }
+    constexpr const Value &operator*() const &noexcept { return value(); }
+
+    constexpr const Error &error() const { return m_error; }
+
+private:
+    std::optional<Value> m_value;
+    Error m_error;
+};
+
+QT_END_NAMESPACE
+
+#endif // QMAYBE_P_H