Introducing Nullable Reference Types in C#. Is there hope for D, too?

[Timon Gehr]

On 22.11.2017 02:09, codephantom wrote:
> On Wednesday, 22 November 2017 at 00:49:02 UTC, Jonathan M Davis wrote:
>> While I definitely don't think that it's generally very hard to avoid 
>> bugs with null pointers/references, telling someone to code correctly 
>> in the first place isn't very useful.
> 
> Fair enough...perhaps I'm being too explicit with my argument.
> 
> However, my point is, that one should not overly rely on some magical 
> compiler for telling you what is 'true'.
> ...

That is not the role of the compiler here. The task of the compiler in 
this circumstance is to tell you what is obvious, not what is true.

> How can a compiler know that G is true if it cannot prove that G is true?
> ...

Because you proved it to the compiler.

> You need to take this into account during your coding. Otherwise the 
> runtime system is your last line of defence.
> 

You seem to assume that Rice's theorem applies to compilers, but not 
programmers. Why is that?