Encapsulates unique ownership of a resource. Resource of type T is
deleted at the end of the scope, unless it is transferred. The
transfer can be explicit, by calling release, or implicit, when
returning Unique from a function. The resource can be a polymorphic
class object, in which case Unique behaves polymorphically too.
Constructor that takes a Unique of a type that is convertible to our type.
Example
static struct S
{
int i;
this(int i){this.i = i;}
}
Unique!S produce()
{
// Construct a unique instance of S on the heap
Unique!S ut = new S(5);
// Implicit transfer of ownership
return ut;
}
// Borrow a unique resource by ref
void increment(ref Unique!S ur)
{
ur.i++;
}
void consume(Unique!S u2)
{
assert(u2.i == 6);
// Resource automatically deleted here
}
Unique!S u1;
assert(u1.isEmpty);
u1 = produce();
increment(u1);
assert(u1.i == 6);
//consume(u1); // Error: u1 is not copyable
// Transfer ownership of the resource
consume(u1.release);
assert(u1.isEmpty);
