How does D improve design practices over C++?

[Walter Bright]

Brad Roberts wrote:
> On Wed, 29 Oct 2008, Walter Bright wrote:
>> Null pointer dereferencing, for example, is a program bug but is not a safety
>> issue because it cannot cause memory corruption.
> 
> Actually, that's not true.  Dereferencing null _can_ corrupt memory.  As 
> you well know, ptr[index] is just ptr + index.  Use a large and accurate 
> enough index and you're out of that first page of memory and back into 
> application memory space.  Find the address of a key stack variable and 
> you've got room for all sorts of fun and mahem.

True, but technically that is not a null pointer dereference. There are 
also ways to deal with it. One is to disallow fixed offsets exceeding 
the protected null space (Java prohibits objects > 64Kb in size for this 
reason). Next is to disallow pointer arithmetic (which is what SafeD 
proposes).

> These are the sorts of bugs in popular enough applications are the things 
> that end up costing companies lots of money to emergency fix.  One of the 
> few recent flash exploits were exactly this type of bug.

You're right, and SafeD should make such exploits impossible.