why std.stdio.File is a struct?

[lumpyzhu via Digitalmars-d]

On Thursday, 20 October 2016 at 07:40:05 UTC, Jonathan M Davis 
wrote:
> On Thursday, October 20, 2016 06:59:12 lumpyzhu via 
> Digitalmars-d wrote:
>> std.stdio.File has reference counter inside,
>> why not std.stdio.File is class?
>
> By using a struct with a reference count, you get deterministic 
> destruction, and the file will be closed as soon as the 
> reference count hits zero. If it were a class, then it would 
> only be closed when the GC happened to collect the memory, and 
> there's no guarantee that it will _ever_ collect the memory 
> (e.g. the GC normally only runs when you call new, so if you 
> never allocate memory again after allocating the File, then the 
> GC will never collect it even if nothing refers to it anymore).
>
> User-defined types that manage system resources are pretty much 
> always better off as structs so that they can have 
> deterministic destruction. Java and C# have a terrible time 
> with stuff like closing files, essentially requiring you to do 
> it manually, because there's no guarantee that the finalizers 
> for their file classes will ever run, and you risk the resource 
> never being released until the program terminates, which can be 
> a big problem. We'd have the same problem if we used a class 
> for std.stdio.File, whereas using a struct works great.
>
> In general, in D, if you don't need inheritance and 
> polymorphism, you probably shouldn't be using a class.
>
> - Jonathan M Davis


thanks..
but structs are copy by value,
In C++, I can use reference to avoid value-copy,

------------------------------------------
class MyClass {....};
void myFunc(const MyClass& a, MyClass& b) {...};

{
       MyClass object;
       myFunc(object);
       // f will destroyed here.
}
------------------------------------------
in c++, I know where the object is destroyed..
but how to convert this c++ code to d?