This is really not correct. I'd say in the most of Europe, you signal left, you take the entire lane and make your turn on the intersection. In many places there are even dedicated zones in front of left lanes (taking the entire width), so that it's obvious cyclists have the right to do so.

And the same thing on roundabouts, if you want to safely ride a roundabout you absolutely have to take the entire lane and not allow cars to overtake you. Otherwise cars exiting the roundabout will run over you.