[Development] QString and related changes for Qt 6

[Matthew Woehlke]

On 13/05/2020 02.33, Lars Knoll wrote:
> On 12 May 2020, at 23:09, Thiago Macieira wrote:
>> I want rules that determine what the API should be without looking at the
>> implementation of those two functions.

You may be disappointed, at least as far as parameters.

> This is one reason why I think we should simply use QString in most of those cases.
> 
> Additionally, QString is a class that owns it’s data, making it the
> class that’s easiest to use and safest. QStringView doesn’t own it’s
> data and as such there are always lifetime considerations that need
> to be taken into account when using it. So using it would make using
> the API harder and more error prone.

That might be true for return values. For parameters, if the *user* 
needs to care whether the function takes a QString vs. QStringView, 
we're doing something wrong. The onus to properly handle a QStringView 
in that case should be entirely on the *implementer* of the API.

...but yeah, if we're talking about return values, that's a whole other 
kettle of fish.

-- 
Matthew