DIP1028 - Rationale for accepting as is

[Walter Bright]

I'd like to emphasize:

1. It is not possible for the compiler to check any declarations where the 
implementation is not available. Not in D, not in any language. Declaring a 
declaration safe does not make it safe.

2. If un-annotated declarations cause a compile time error, it is highly likely 
the programmer will resort to "greenwashing" - just slapping @safe on it. I've 
greenwashed code. Atila has. Bruce Eckel has. We've all done it. Sometimes even 
for good reasons.

3. Un-annotated declarations are easily detectable in a code review.

4. Greenwashing is not easily detectable in a code review.

5. Greenwashing doesn't fix anything. The code is not safer. It's an illusion, 
not a guarantee.

6. If someone cares to annotate declarations, it means he has at least thought 
about it, because he doesn't need to. Hence it's more likely to be correct than 
when greenwashed.

7. D should *not* make it worthwhile for people to greenwash code.

It is, in a not-at-all obvious way, safer for C declarations to default to being 
safe.