import std.stdio;

​

struct A

{

    void opAssign(A rhs) { writeln("Called A.opAssign"); }

    this(this) { writeln("Called A's postblit"); }

}

​

struct B

{

    A a;

    void opAssign(B rhs) { writeln("Called B.opAssign"); }

    this(this) { writeln("Called B's postblit"); }

}

​

void main()

{

    B b1, b2;

    b1 = b2;

}