Rvalue references - The resolution

[deadalnix]

On Saturday, 4 May 2013 at 21:48:25 UTC, Walter Bright wrote:
> On 5/4/2013 2:22 PM, deadalnix wrote:
>> I still think this is inferior to Rust's solution and like to 
>> see ref as a
>> equivalent of the Rust burrowed pointer. It achieve the same 
>> safety at compile
>> time instead at runtime, and incurs no extra complexity except 
>> in some very rare
>> cases (when you have a function taking several arguments by 
>> ref and returning
>> also by ref and the lifetime of the returned ref isn't the 
>> union of the lifetime
>> of the ref parameters - a very specific case).
>
> As you say, D ref's are analogous to Rust's borrowed pointers, 
> and for the escaping ref problem, Rust requires additional 
> annotations (much like the 'scope ref' proposal).
>
> http://static.rust-lang.org/doc/tutorial-borrowed-ptr.html#returning-borrowed-pointers
>
> The runtime check is because Andrei & I really didn't like 
> requiring additional annotations.

Where you miss the point, is that these annotations may be 
omitted (and they are most of the time). When nothing is 
specified, the lifetime of the returned reference is considered 
to be the union of the lifetime of parameters lifetime, which is 
what you want in 99% of cases.