Returning const &

[frenk_castle]

In my app I have I class that handles file IO. I have a protected method that contains the code for reading from a file. Basically every method that reads from a file makes some preparations and that calls this protected method.

QStringList WODAL::readFile(const QString &name)
        {
            QStringList result;
            QFile file(name);
            QTextStream stream;
 
            if(file.open(QIODevice::ReadOnly | QIODevice::Text))
            {
                stream.setDevice(&file);
                while(!stream.atEnd())
                {
                    result.append(stream.readLine());
                }
            }
 
            file.close();
 
            return result;            
        }

QStringList WODAL::readFile(const QString &name)
        {
            QStringList result;
            QFile file(name);
            QTextStream stream;

            if(file.open(QIODevice::ReadOnly | QIODevice::Text))
            {
                stream.setDevice(&file);
                while(!stream.atEnd())
                {
                    result.append(stream.readLine());
                }
            }
            
            file.close();
            
            return result;            
        }

To copy to clipboard, switch view to plain text mode 

When I change the return type from QStringList to const QStringList& I get the compiler warning returning of the reference to a local variable, or something like that. Since I have another class which is mostly a property container. It has lot of members that only have setters and getters I wanted to make a getter that is for instance like this

const QString& WOIDL::clientName()
{
    return m_clientName;  //m_clientName is of QString type
}

const QString& WOIDL::clientName()
{
    return m_clientName;  //m_clientName is of QString type
}

To copy to clipboard, switch view to plain text mode 

For this getter I don't get the warning because m_clientName is not a local variable from some method which will be destroyed upon returning but a class member. My question is: Is it ok to use const QString& and const QStringList& in these cases or not? Its been a while since I read on these topics and I am not sure when is return variable destroyed. For instance will this code be ok if I write it in some method of the WODAL class in case return type is const QStringList&?

QStringList list;
QString name("somefile");
 
list = readFile(name);

QStringList list;
QString name("somefile");

list = readFile(name);

To copy to clipboard, switch view to plain text mode 

or

const QStringList& WODAL::loadClientList()
{
    return readFile(m_clientListFileName);  //m_clientList is of QString type and was previously initialized
}

const QStringList& WODAL::loadClientList()
{
    return readFile(m_clientListFileName);  //m_clientList is of QString type and was previously initialized
}

To copy to clipboard, switch view to plain text mode 

Thanks in advace.