Safety, undefined behavior, @safe, @trusted

[Don]

Walter Bright wrote:
> grauzone wrote:
>> If you mean memory safety, then yes and will probably forever be for 
>> all practical uses (unless D gets implemented on a Java or .net like VM).
> 
> A VM is neither necessary nor sufficient to make a language memory safe. 
> It's all in the semantics of the language.

In practice, the big disadvantage which D has is that it can make calls 
to C libraries which are not necessarily memory safe -- and this is an 
important feature of the language. Dealing with the external, 
uncheckable libraries is always going to be a weak point. Both Java and 
.net have mitigated this by rewriting a fair chunk of an OS in their 
libraries. That's probably never going to happen for D.