Vision for the D language - stabilizing complexity?

[John Colvin via Digitalmars-d]

On Tuesday, 12 July 2016 at 05:37:54 UTC, Walter Bright wrote:
> On 7/11/2016 10:15 PM, Shachar Shemesh wrote:
>> D says any such cast is UB.
>
> That's why such casts are not allowed in @safe code. There's 
> also no way to write a storage allocator in @safe code.
>
> Code that is not checkably safe is needed in real world 
> programming. The difference between D and C++ here is that D 
> provides a means of marking such code as unsafe so the rest can 
> be checkably safe, and C++ does not.

Code that *could* cause undefined behaviour given certain inputs 
is unsafe code. Can be ok if you're careful.

Code that *does* do undefined behaviour isn't just unsafe, it's 
undefined. Never OK.


If casting away immutability is undefined behaviour in D, then 
all paths of execution* that do it are undefined.

For the previous statement to be false, you must define cases 
where casting away immutability *is* defined.