On 1/3/2014 11:42 PM, ilya-stromberg wrote:
NULL pointer means that I don't have any valid object, and it's good situation.
But there are a lot of situations when function must take a valid object (at
least NOT NULL pointer). D allows:
1) use `if(p is null)` and than throw exception - it will be safe, but I have
additional `if` check
2) ues `assert(p !is null)` - theoretically, it will be safe, but program can
have different situation is realise mode and fails (for example, because nobody
provide the same example in debug mode)
3) do nothing - programmer just forgot to add any checks
Also, I must to add unit tests for every posible case usage of that function
with a valid object. So, it's kind of dynamic typing that can be done by
compiler type system.
So, in a few cases null pointers are a safety issue.
I believe this is a misunderstanding of what safety is. It means memory safety -
i.e. no memory corruption. It does not mean "no bugs".
Memory corruption happens when you've got a pointer to garbage, and then you
read/write that garbage.
Null pointers seg fault when they are dereferenced, halting your program. While
a programming bug, it is not a safety issue.
