29-May-2013 21:01, Timon Gehr пишет:
On 05/29/2013 03:15 PM, Dmitry Olshansky wrote:
[snip]
In fact most of Phobos they already use in place lambdas to get mock
l-values of type T.
This begs the question of usefulness of T.init and should ALL types have
it.
T.init also has some other subtle issues:
void bar(short x){ }
void foo(T)(T arg) if(is(typeof(bar(T.init)))){
bar(arg);
}
Implying that if I pass int it would observe that bar(int.init) -->
bar(0) works by range propagation? Then yes, yet another reason not to
use it in constraints.
It is easy to instantiate foo such that the constraint passes and the
function body does not compile.
Since we have @disable this() I'd say T.init is no longer as useful and
general at best it defines binary mask to blit over uninitialized
variables. In essence it's T.uninitialized.
Well, 'uninitialized' may mean it could be random garbage.
Well in case of @disable this() structs it would contain definite
garbage (as in deterministic) :)
--
Dmitry Olshansky
