I now compile with the following flags,
```
# DIP25 , return ref
# DIP1000 , scoped pointers
# --boundscheck=on , perform array bounds check
# --safe-stack-layout , enable safe stack layout
#--D , generate documentation,
#--g , symbolic debug info
#--d-debug ,it enables all debug checks (i.e. asserts,
boundschecks, contracts and invariants) as well as acting as
-d-debug=1.
#--w , treat warning as error
#--de: halt on deprecated
ldc2 --dip1000 --dip25 --safe-stack-layout --boundscheck=on --D
--g --w --de --d-debug test.d
```
