all OS functions should be "nothrow @trusted @nogc"

[Shachar Shemesh via Digitalmars-d]

On 25/07/17 17:11, ag0aep6g wrote:
> On 07/25/2017 03:50 PM, Shachar Shemesh wrote:
>> The title really does says it all. I keep copying OS function 
>> declarations into my code, just so I can add those attributes to them. 
>> Otherwise I simply cannot call "signalfd" and "sigemptyset" (to name a 
>> couple from my most recent history) from @safe code.
> 
> Not all OS functions can be `@trusted`.
> 
> I don't about `signalfd` and `sigemptyset`, but `read` [1] can't be 
> `@trusted`, for example. It takes pointer and length separately, and the 
> pointer is a `void*`. That's not safe at all.

And, indeed, the code calling "read" shouldn't be able to do that as 
@safe. Read itself, however, is trusted (because, let's face it, if you 
cannot trust the kernel, you're screwed anyways).

Having said that, I have no objection to excluding the "pointer+length" 
system calls from the above rule. They are, by far, the minority of 
system calls.

Shachar