deserialization: creating a class instance without calling constructor

[Timothee Cour via Digitalmars-d-learn]

Can I create an instance of A without calling a constructor? (see below)
Use case: for generic deserialiaztion, when the deserialization library
encounters a class without default constructor for example (it knows what
the fields should be set to, but doesn't know how to construct the object).

class A{
  int x=2;
  this(int x){
    this.x=x;
  }
}


This came up here:
https://github.com/msgpack/msgpack-d/issues/54#issuecomment-104136148
I provide some hacky solution for that in that thread but I suspect it's
not safe and something is missing.