Reported here: http://lists.trolltech.com/pipermail/qt-creator/2009-December/005488.html

Due to missing a space between >>, the following example leads to completion of invalid code:

class A {
    void foo(QVector<QVector<float> > &bar);
};

Using the autocomplete of the function arguments in the implementation will yield:

void A::foo(QVector<QVector<float>> &bar);