Move Constructors - Converting Lvalues to Rvalues

[Timon Gehr]

On 10/3/24 01:07, Manu wrote:
> On Thu, 3 Oct 2024 at 03:21, Walter Bright via Digitalmars-d 
> <digitalmars-d at puremagic.com <mailto:digitalmars-d at puremagic.com>> wrote:
> 
>     On 10/1/2024 1:15 PM, Timon Gehr wrote:
>      > I guess the new implementation you have in mind is something like
>     the following?
>      >
>      > ```d
>      > auto move(T)(ref T arg)=>__rvalue(arg);
>      > ```
> 
>     Not exactly. __rvalue would also convert an rvalue to an rvalue.
> 
> 
> -preview=rvaluerefparams addresses this; it allows an rvalue to be 
> supplied to the lvalue there. It's actually an essential mechanic to 
> this whole thing, because it will allow the appropriate selection of 
> copy/move overloads where a type may define either one, or both. If a 
> copy and/or move constructor exists, it needs to select the proper one, 
> and the -preview handles that properly as is.

`-preview=rvaluerefparam` allows you to treat an rvalue as an lvalue 
implicitly in some contexts.

`__rvalue` allows you to treat an lvalue explicitly as an rvalue, so it 
will be moved.

I fail to see how those are related.