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

[Thiago Macieira]

On Saturday 17 October 2015 01:18:06 Marc Mutz wrote:
> If you need a real-world example of where QStringView would be handy: Some 
> 3rd-party code returns you a char16_t *path, and you want to perform a 
> QDir::cd(). Currently, you need to create a QString (which allocates). Had 
> QDir::cd() taken a QStringView, you wouldn't have that allocation.

Bad example. You can use QString::fromRawData. While that today allocates the 
d pointer, for Qt 6 it wouldn't (null d pointer) and there would be no code 
change for the user.

There is, however, the danger of fromRawData: you need to be sure the called 
function won't try to store the QString. With a QStringView or the unsharable 
QString that Brano proposed in the other email, it would be clear that a deep 
copy needs to happen.
-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center