QVector.push_back problem...

Hello to all,

i've used to be a programmer but i'ts been a long time (more than 8 years) since i've done any programming. I'm now getting back in shape by learning to program with Qt4.

Here's my problem so far with the following code:
In the header file:

Code:

---

QVector<QPoint> m_cheatTrajectoryPt;

---

Code:

---

m_cheatTrajectoryPt.push_back(QPoint(qRound(x), height() - 1 - qRound(y)));

---

And here is the compile error that puzzles me:

Code:

---

cannonfield.cpp: In member function 'QRect CannonField::shotRect() const’:
cannonfield.cpp:134: erreur: passing 'const QVector<QPoint>' as ‘this’ argument of ‘void QVector<T>::push_back(const T&) [with T = QPoint]’ discards qualifiers

---

Any help would be greatly appreciated!

Thanks!

Luc

Hi,

Quote:

---

Originally Posted by luche

I'm now getting back in shape by learning to program with Qt4.

---

Remember that in order to be successful with Qt you need to know C++. Qt is not a programming language. :)

Quote:

---

cannonfield.cpp: In member function 'QRect CannonField::shotRect() const’:
cannonfield.cpp:134: erreur: passing 'const QVector<QPoint>' as ‘this’ argument of ‘void QVector<T>::push_back(const T&) [with T = QPoint]’ discards qualifiers

---

You are trying to modify a member variable (m_cheatTrajectoryPt) in a const method (CannonField::shortRect). A const method shouldn't change the state of an object.

Quote:

---

Originally Posted by jpn

Hi,

Remember that in order to be successful with Qt you need to know C++. Qt is not a programming language. :)


You are trying to modify a member variable (m_cheatTrajectoryPt) in a const method (CannonField::shortRect). A const method shouldn't change the state of an object.

---

I'm rusty ;)

Thanks for your help :cool: