DIP1028 - Rationale for accepting as is

[Johannes Loher]

On Tuesday, 26 May 2020 at 03:37:29 UTC, Walter Bright wrote:
> He can look at unattributed declarations.

The issue is, you have to know about that beforehand. In the 
other situation, you explicitly get warned by the compiler (by 
the compile error) that that something dangerous is going on.

Also, this means, there are now 2 different things to look for: 
@trusted function declarations and unannotated extern(C) 
declarations. The latter is much harder to search for (as Andrei 
also noted in his reply) and it's just much simpler to only have 
one escape hatch to look out for. It is also a very weird special 
case. @safe means no memory corruption is possible except for any 
@trusted declarations and any unannotated extern(C) declarations, 
wrongfully @safe extern(C) declarations and wrongfully @trusted 
extern(C) declarations. This just doesn’t sound right.

> The whole debate boils down to "is greenwashing better, more 
> honest, more debuggable than leaving things unattributed?" No 
> on all three accounts.

The question should be rephrased: „Is explicit greenwashing by 
the developer better, more honest, more debuggable than implicit 
greenwashing by the compiler?“ Yes for better and more debuggable 
for the reasons that have already been mentioned so many times. 
Regarding honesty: In your variant, the compiler is dishonest,  
in the other variant, the developer is dishonest.

Just think about what the developer's reaction would be in the 
situation I described in my last post, when he actually finds the 
issue.

In your variant, the developer will be questioning why the 
compiler did not help him at all with realizing that there might 
be a problem. It is very likely that he blames the issue on the 
compiler.

In the other variant, he will realize that this something he had 
been warned about by the compiler and that he made a careless 
wrong decision and that it is his own fault. In the future he 
will be likely more careful when it comes to annotating stuff 
with @trusted. So this even has an educational effect.