On 8/31/2014 6:47 AM, Dmitry Olshansky wrote:
import core.stdc.string;
import trusted;
void main() @safe
{
char[] msg = "Hello!".dup;
char[] msg2 = msg;
import trusted; // may also use static import for absolute clarity
assert(call!memcmp(addrOf(msg[0]), addrOf(msg2[0]), msg.length) == 0);
}
I don't agree with the notion of having primitives that provide escapes from
@safe - it means the interleaving of @safe and @system code becomes too easy,
and too easy to miss.
I also don't agree with the notion of having @trusted blocks of the form:
@trusted {
... system code ...
}
We already have a mechanism to do that - @trusted nested functions. The code
example becomes:
void main() @safe {
char[] msg = "Hello!".dup;
char[] msg2 = msg;
void checkEquals(const char[] msg, const char[] msg2) pure @trusted {
assert(msg.length == msg2.length);
assert(memcmp(msg.ptr, msg2.ptr, msg.length) == 0);
}
checkEquals(msg, msg2);
}
Granted, this can be abused to subvert the @safe/@trusted/@system system, but
that has always been the case. Note that I added an assert to make checkEquals()
actually trustworthy. The QA code reviewer can still grep for @trusted and flag
them for special review.
These sorts of nested functions should inline and pose no extra overhead.
