Pimpl idiom without using dynamic memory allocation

we want to use pimpl idiom for certain parts of our project. These parts of the project also happen to be parts where dynamic memory allocation is forbidden and this decision is not in our control.

So what i am asking is, is there a clean and nice way of implementing pimpl idiom without dynamic memory allocation?

Edit
Here are some other limitations: Embedded platform, Standard C++98, no external libraries, no templates.