Issues with qDebug and QString const reference

Question

Have a class which have the following functions:

FileInfoWrapper(const QFileInfo &_fileInfo) : fileInfo(_fileInfo) {}

const QString& FileName() const { return fileInfo.fileName(); }

But when I do this:

QFileInfo info(somePath);

qDebug() << info.absoluteDir(); // works

FileInfoWrapper test(info);

qDebug() << test.FileName(); // this crashes the entire application

When I remove the const & from the string return, it works. It's like << doesn't work with references. Whats wrong and why does it crash?

Answer 1

You return reference to the QString which is destroyed when you leave FileName() function.

Answer 2

std::cout doesn't know QString, you need to convert it to std::string or const char*

Use QString::toStdString to convert to std::string, e.g.:

std::cout << test.FileName().toStdString();