Hi Ferenc,
for reusable singleton pattern with php 5.3 > http://www.slideshare.net/fabpot/design-patternrevisitedphp53 > slide 11 and 12 > As Tom already pointed out - there is that lock-down of your parent(s) to singletons with this type of implementation and there are other shortcomings when used with SPL, for example: class Test extends ArrayObject { } Without creating some sort of intermediate ArrayObjectSingleton class you can't make Test a singleton (and traits would solve that). /Simas
