[Development] QTCS2019 Notes from QtQml session

Eike Ziller Eike.Ziller at qt.io
Mon Nov 25 12:30:09 CET 2019

> On 25. Nov 2019, at 11:03, Giuseppe D'Angelo via Development <development at qt-project.org> wrote:
> Il 25/11/19 10:25, Eike Ziller ha scritto:
>>> ?
>> Similar things can happen in C++ with method names.
>> C++ got the ‘override’ keyword to make these breakages detectable by tooling.
>> It looks to me like the case id==propertyname would also be detectable by tooling?
> What do you mean? Can you make an example? The whole point of shadowing in C++ is to make sure that the above does NOT break.

Funny things can happen if the new method in the base class is virtual.

// in library libA
class A {

// in user code
class B {
  void foo();

now class A changes to

class A {
  virtual void foo();

Code in libA now calls “foo” on instances of subclasses of A, including instances of B, with funny results.

I vaguely remember that we had a case of that in Qt Creator where Qt introduced some method in one of its classes.

Eike Ziller
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