dip1000 and preview in combine to cause extra safety errors

[Walter Bright]

On 6/8/2022 9:22 AM, Steven Schveighoffer wrote:
> The reality is that people are (mostly) only dealing with the existing 
> implementation, until it stops working. But to silently break it, and silently 
> break it with *memory corruption* does not seem an appropriate penalty.

The point of @system code is people can do whatever they want.

The answer is to make @safe the default. But that DIP was rejected.