default value fails if identifier is a struct

The thrift IDL specifies that a field can be a assigned a default ConstValue, which can be an identifier, possibly a struct. However, the compiler rejects this input with the error: type error: const was declared as struct/xception.

For this example input:

struct A {
  1: string name = ""
} 
const A DEFAULT_A = {}
struct B {
  1: A a = DEFAULT_A
} 

The expected output would be something like (in Java):

public class B {
  public B() {
    this.a = new A(Constants.DEFAULT_A);
  }
}

Note that a copy of DEFAULT_A is used instead of the DEFAULT_A instance itself.