ref type versus ptr type on input

[monarch_dodra]

On Sunday, 29 December 2013 at 21:47:52 UTC, Namespace wrote:
> On Sunday, 29 December 2013 at 19:42:39 UTC, Jonathan wrote:
>> If I want to write a function that operates on a struct
>>
>> struct S { }
>>
>> What are the differences between:
>>
>> void(S* s)
>>
>> void(ref S s)
>
> You cannot set a default value (like null) for ref parameters, 
> but you can for pointer.

Well, a ref *can't* be null. In terms of default value, both can 
have them, in terms of referencing a static object though.

The only functional difference I know of in pass-by-ref vs 
pass-by-pointer is indeed the null pointer:
- Pass by pointer means you *can* pass a null (yay).
- But pass by ref means the implementation does not have to worry 
about null references (yay).