deserialization: creating a class instance without calling constructor

[John Colvin via Digitalmars-d-learn]

On Thursday, 21 May 2015 at 09:06:59 UTC, Timothee Cour wrote:
> 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.

For a start I'm pretty sure you want to be calling 
core.memory.GC.malloc not core.stdc.stdlib.malloc, otherwise you 
leak the memory.