[Development] RFC: Proposal for a semi-radical change in Qt APIs taking strings

[Thiago Macieira]

On Monday 19 October 2015 18:38:52 Smith Martin wrote:
> >Again, please try writing this method:
> Doesn't that example just mean there are some classes that can't have a
> QStringView API? A class should have a QStringView API if it can be used
> safely.

Right. I'm simply saying that "if it can be used safely" is very, very 
restricted.

Suppose you have in v1:

class Foo
{
	QString m_data;
public:
	QStringView data() const;
};

Which looks fine and works without dangling references. Then in v2, you need to 
do this:

class Foo
{
	QByteArray m_data;
public:
	QStringView data() const;
};

This API here simply cannot exist because the returned value would be a 
dangling reference.

Therefore, QStringView returns must be treated like references: only in 
exceptional cases.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center