share

static struct Foo{
    ControlBlock!(int, int) c;
    int i;

    this(int i)pure nothrow @safe @nogc{
        this.i = i;
    }
}

{
    auto x = IntrusivePtr!(shared Foo).make(123);
    assert(x.useCount == 1);

    shared s1 = share(x);
    assert(x.useCount == 2);


    import core.lifetime : move;
    shared s2 = share(x.move);
    assert(x == null);
    assert(s2.useCount == 2);
    assert(s2.load.get.i == 123);

}

{
    auto x = IntrusivePtr!(Foo).make(123);
    assert(x.useCount == 1);

    ///error `shared IntrusivePtr` need shared `ControlType` and shared `ElementType`.
    //shared s1 = share(x);

}