About ref used for performance reasons with struct

[deadalnix]

On Monday, 11 February 2013 at 15:48:32 UTC, Michel Fortin wrote:
> On 2013-02-11 06:52:28 +0000, "deadalnix" <deadalnix at gmail.com> 
> said:
>
>> When a function accept a struct, the compiler is free to use 
>> that function, or an altered one taking a reference as 
>> parameter.
>
> When designing the ABI, you can either create the copy on the 
> caller's side, or the callee's side. If I'm understanding well, 
> you want to have two versions of each function, one copying on 
> the caller's side, one copying on the callee's side,

That is blatantly wrong.

You don't have, the compiler is allowed to, and the copy on 
callee side isn't mandatory.