Move Constructors - Converting Lvalues to Rvalues

[Dukc]

On Tuesday, 1 October 2024 at 17:37:37 UTC, Walter Bright wrote:
> On 10/1/2024 12:27 AM, Dukc wrote:
>> Why special syntax? `move` is a DRuntime function so it's 
>> expected that it can have special semantics, even without 
>> special syntax.
>
> Converting to an rvalue is an enabler of other functions, too, 
> not just move. __rvalue is a building block, not a complete 
> function.

`move` _is_ the `__rvalue` building block, at least in principle. 
It accepts an lvalue and returns a rvalue, without executing the 
destructor or move constructor of the type in question.

It does set the lvalue to it's `.init` value, but this can be 
elided by the optimiser if the lvalue is not used again, assuming 
the destructor doesn't side-effect in any way.