Motive behind !empty() with front() instead of Optional front()

[Andrei Alexandrescu]

On 4/6/21 5:14 PM, Per Nordlöw wrote:
> On Tuesday, 6 April 2021 at 21:09:13 UTC, Paul Backus wrote:
>> For non-copyable types. It's actually needed in both cases--we would 
>> need DIP 1040 (or something similar) to get rid of it.
> 
> So let's help Walter getting DIP-1040 accepted then. :)
> 
> What else is forward needed for? The doc says
> 
> "Forwards function arguments while keeping `out`, `ref`, and `lazy` on
> the parameters."
> 
> Why can't the compiler do that for us?

Because sometimes you want the usual semantics, i.e. create a copy of 
the argument.

These things are difficult to automate. I don't think a simple solution 
exists.