Lets have this code:
```D
import core.lifetime : forward;
import core.stdc.stdio;
import std.algorithm : move;
struct Value(T) {
private T storage;
this()(auto ref T val) {
storage = forward!val;
}
ref inout(T) get() inout {
return storage;
}
}
Value!T value(T)(auto ref T val) {
return Value!T(forward!val);
}
auto ref unwrap(EX)(auto ref EX res) {
return res.get();
}
struct Foo {
int n;
@disable this(this);
~this() { printf("~this(%d)\n", n); }
}
auto gen() {
Foo f;
f.n = 42;
return value(f.move());
}
void main() {
Foo f;
f = gen().unwrap.move;
}
```
As I understand it unwrap in `f = gen().unwrap.move` can't be
called by ref (as gen() returns rvalue) so it would force the
`Value` to be copied but as it holds non copyable struct, it
can't be and so it should end up with a compiler error.
But the code outputs:
```
~this(0)
~this(0)
~this(0)
~this(42) <- this is a copy (that shouldn't exist) being destroyed
~this(0)
~this(42)
```
This could cause unwanted resource cleanup on a seemingly non
copyable structs.
Bug or feature? :)
