Move Constructors - Converting Lvalues to Rvalues

[Walter Bright]

On 9/30/2024 12:37 PM, Timon Gehr wrote:
> On 9/30/24 18:05, Walter Bright wrote:
>>
>> So, does anyone have any brilliant ideas for how to make the compiler treat an 
>> lvalue as an rvalue?
> 
> Well, with DIP1040 this is automatically the case for last uses.

The trouble with last uses is detecting them. It's a variation on live variable 
DFA, which the optimizer does for variables. Indirections cannot be reliably 
tracked, and variables which have their address taken similarly can't reliably 
have DFA done on them.

In any case, I decided for at least the first implementation to require an 
explicit "convert to rvalue" operation to get the benefits of a move 
construction. I'm pretty sure it will deliver most of what we want.