In the following code, Bar is an element of struct Foo. Is there 
a way to avoid a call to ~Bar when ~Foo is getting executed?
// >>>>>>>>>>
import std.stdio;
struct Foo {
   Bar bar;
   ~this() {
     writeln("~Foo");
     // some code that disables call to ~Bar
   }
}
struct Bar {
   ~this() {
     writeln("~Bar");
   }
}
void main() {
   Foo foo;
}