Problem with const correctness

[Dan]

On Monday, 10 December 2012 at 11:39:24 UTC, Thiez wrote:
> On Saturday, 8 December 2012 at 21:47:32 UTC, Dan wrote:
>> My approach is to have a general dup function. I call it gdup, 
>> for global dup so the name does not conflict with the existing 
>> dup. It dup's fields recursively. Feel free to have a look and 
>> any suggestions appreciated. Would greatly appreciate if 
>> seasoned D developers like (Ali,  bearophile, ...) would 
>> review - as I use these mixins to simplify development with 
>> structs.
>
> What would happen to the recursive dup if the structure 
> contains a cycle (e.g. A has a reference to B, which has a 
> reference to C, which has a reference to the original A)?

By reference I assume you mean pointer.

That would be an infinite loop. If you have a compile time cycle 
you would likely need your own custom dups anyway, as you are 
doing low level and heap allocating already. But for the simpler 
cases without cycles, if dup encounters a pointer it creates a 
new instance on the heap (if compilation is possible) and dup's 
into it.