README-returning-data-from-temporary.md

returning-data-from-temporary

Warns when returning the data from a QByteArray that will soon be destroyed.

Examples

QByteArray b = ...;
return b.data();

return funcReturningByteArray().data();
return funcReturningByteArray().constData();

const char * getFoo()
{
    QByteArray b = ...;
    return b; // QByteArray can implicitly cast to char*
}

    const char *c1 = getByteArray();
    const char *c2 = str.toUtf8().data();

Note that in some cases it might be fine, since the method can return the data of a global static QByteArray. However such code is brittle, it could start crashing if it ceased to be static.