Struct copy, how?

[Daniel Keep]

Christopher Wright wrote:
> Daniel Keep wrote:
>> Off the top of my head, it wouldn't be terribly hard.
>>
>> What you would need is a global 'ddup' (deep-dup) function.  The 
>> generic case would look something like:
>>
>> T ddup(T)(ref T value)
>> {
>>     T result;
>>     foreach( i,f ; value.tupleof )
>>         result.tupleof[i] = ddup(f);
>>     return result;
>> }
>>
>> You'd then have to use either specialisation or lots of static if's to 
>> account for reference types, allocating new memory as necessary.
>>
>> Can't see any particular reason why you couldn't do it...
>>
>>   -- Daniel
> 
> You want ddup to be polymorphic. Let's say you have a class with no 
> default constructor, or a class that starts listening on a socket with 
> some default local port -- in the first case, you couldn't ddup it 
> without some ugliness; in the second, you could ddup it, but you'd get 
> an exception because the port's already in use.
> 
> It would suffice to have an IClonable interface, and to check structs 
> for a ddup property.

Obviously, you'd need to have the class support it itself; but the 
original question was in regards to a struct deep copy.  :P

For reference, I've written a generic serialise/deserialise pair of 
functions that do, more or less, the same thing, so it can be done.

   -- Daniel