c++ design problem
 

i have two classes. One is room and the other is container.Room is the class which you write, container is a 3rd party class, you can't change
the class definition of container.
in the constructor of container, large amount of memory is allocated.
In the ctor of room, a small amount of memory is allocated.
Would you go in for an inheritance relationship or a composition between 'room' and 'container' ?

A few conditions:
1. Container has functions like open and close which even room can use and MUST re-use
2. Containers ctor should not be called as it allocates huge amounts of memory.