Re: const and immutable values, D vs C++?

[Ola Fosheim Grøstad via Digitalmars-d-learn]

I also find the following behaviour a bit unclear:

struct node0 {int value; node0* next;}
struct node1 {int value; const(node1)* next;}
struct node2 {int value; immutable(node0)* next;}
T mk(T)(){
    T tmp = {2019, null};
    return tmp;
}

node1 mk_node1(){
    node1 tmp = {2019, null};
    return tmp;
}

node2 mk_node2(){
    node2 tmp = {2019, null};
    return tmp;
}


void main() {
    immutable x0 = mk!node0();  //succeeds?
    immutable x1 = mk!node1();  //succeeds?
    immutable x2 = mk!node2();  //succeeds?
    immutable y1 = mk_node1();  //fails
    immutable y2 = mk_node2();  //succeeds, so only first child 
has to be immutable?
}