I finished reading "Book" and now I read "Rust by Example".
Here I found example of code
This example output is
Point occupies 16 bytes on the stack Rectangle occupies 32 bytes on the stack Boxed point occupies 8 bytes on the heap Boxed rectangle occupies 8 bytes on the heap Boxed box occupies 8 bytes on the heap Unboxed point occupies 16 bytes on the stack
All boxed data only show size of pointer, not size of data, but in my knowledge pointers live on stack and not on heap. They only point to data on heap. So, in my option this example is not right. It should say:
Boxed point occupies 8 bytes on the stack and 16 bytes on the heap.
Now it looks like point on the heap takes less memory than point on stack. Even boxed rectangle occupies only 8 bytes on heap. So if we moved all this forum data on heap it would take only 8 bytes in RAM