createSlimRC

auto a = createSlimRC!double(10);
auto b = a;
assert(*b == 10);
*b = 100;
assert(*a == 100);

static class C
{
    int index;
    double value;
    ref double bar() @safe pure nothrow @nogc { return value; }
    this(double d) { value = d; }
}
auto a = createSlimRC!C(10);
assert(a._counter == 1);
auto b = a;
assert(a._counter == 2);
assert((*b).value == 10);
b.value = 100; // access via alias this syntax
assert(a.value == 100);
assert(a._counter == 2);

struct S
{
    double e;
}
struct C
{
    int i;
    S s;
    // 'alias' should be accesable by reference
    // or a class/interface
    alias s this;
}

auto a = createSlimRC!C(10, S(3));
auto s = a;
assert(s._counter == 2);
assert(s.e == 3);

static class C
{
    int index = 34;
}
assert(createSlimRC!C.index == 34);