On 3/5/18 6:41 AM, Nordlöw wrote:
On Wednesday, 28 February 2018 at 20:07:50 UTC, Steven Schveighoffer wrote:
auto x = cast(Object)((cast(size_t *)null) + 1);
Thanks, how do I store it as enum or static immutable struct member?
In
@trusted pure unittest
{
class C { int value; }
C x;
C y = cast(C)((cast(size_t*)null) + 1); // indicates a lazily
deleted key
struct S
{
enum C hole1 = cast(C)((cast(size_t*)null) + 1); // TODO make work
static immutable C hole2 = cast(C)((cast(size_t*)null) + 1); //
TODO make work
}
}
both `enum` and static` immutable` member declarations fail to compile
with the same errors:
Error: cannot perform pointer arithmetic on non-arrays at compile time
Error: cannot perform pointer arithmetic on non-arrays at compile time
My only possible solution so far is to return the expression from an
inline member function which I guess cannot be optimized as good as
comparing to a compile-time value.
Weird, I would have expected to be able to map addresses at compile
time, I suppose the way you could work it is:
pragma(inline, true)
C lazyDeleted() pure nothrow @trusted { return
cast(C)((cast(size_t*)null) + 1); }
Then you can simply use this like it was an enum or immutable. It should
go away in terms of a function call.
-Steve
