Doc not at date ?
Why the doc 5.0 : http://qt-project.org/doc/qt-5.0/qtmultimedia/multimediawidgets-player.html
Say about signal : connect(controls, SIGNAL(play()), player, SLOT(play()));
Is not the currenct connect
I think you are asking why the docs are using the original style for connect() and not the new style. The new style is optional. This does not make the documentation incorrect or out of date. If you want to use the optional new-style connect() then go right ahead.