---
vector<memblock> of 10 elements:
---

0 
1 2 
3 4 5 
6 7 8 9 
10 11 12 13 14 
15 16 17 18 19 20 
21 22 23 24 25 26 27 
28 29 30 31 32 33 34 35 
36 37 38 39 40 41 42 43 44 
---
size() = 10, max_size() = SIZE_MAX/elsize, empty() = false
back()->size() = 5
back()->size() = 40
36 37 38 39 40 41 42 43 44 
---
vector of 7 elements backwards:
---
28 29 30 31 32 33 34 35 
21 22 23 24 25 26 27 
6 7 8 9 
3 4 5 
1 2 
0 

---