I draw a closed curve and use extrude to get a solid. When I change the curve, the solid updates automatically. The problem is that when I move (even by accident) the solid, then the connection breaks and the solid is not modifiable. Undo is not always the solution because sometimes I 've already created 2-3 objects before see the mistake.
What I suggest is to have some kind of connection between the curve and the solid that won't break when moving one of them.Actually, I would prefer not to have the curve as an object but to be able to make it appear when we want to modify the solid.
That would be possible only with a new "edit" command. That way, every solid would include the object it was created from and a copy of that object would also include the curve.

An example showing the need of such command and way of doing things is the following :
1. Make a circle, extrude, you have a cylinder.
2. Select the circle, copy and paste to the same position. (just Ctrl+C and Ctrl+V).
3. Move the second circle to the top of the first cylinder.
4. Extrude that circle and you have a second cylinder on top of the other.
5. Try to modify the two circles, you get update objects automatically.
6. Use boolean, union and select the two cylinders.

***What you get is a dead object***

You can transform the circles to whatever you want, the solid doesn't update.

If we could constantly connect the circles and the cylinders, this wouldn't happen.

I would like to hear your opinion about this...