On Tue, 05 Feb 2013 13:33:35 -0500, Andrei Alexandrescu <[email protected]> wrote:

Walter and I reviewed the discussion and had a long talk. We are very seriously considering banning the use of & against a ref result from a function (and actually ref parameters and even struct members in @safe code). One would still be able to take the address of a field in a class because that's assumed to live on the GC heap.

What about structs that live on the heap? e.g. a struct element of an array, or a struct member of a class instance.

I think the point about @safe code is moot, aren't pointers disallowed in safe code anyway?

To get the address of an object in @system code without resorting to operator& at all, we're considering adding a stdlib function implemented like this (there are several other ways, this is just for illustration):

@system T* addressOf(T)(ref T obj)
{
     static T* id(T* p) { return p; }
     auto idr = cast(T* function(ref T)) id;
     return idr(obj);
}


I think a cast would be sufficient:

cast(int *)(&refparam); // understood that a cast is required

To jump through this machinery to turn a reference into a, um... reference, seems like a huge waste of code space and resources.

-Steve

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