Tuple DIP

[Exil]

On Monday, 3 June 2019 at 17:43:36 UTC, Timon Gehr wrote:
> On 20.09.18 19:08, Guillaume Boucher wrote:
>> On Saturday, 13 January 2018 at 18:28:55 UTC, Timon Gehr wrote:
>>> However, this proposal is independent of all the other ones, 
>>> so in the end it is up to Walter and Andrei.
>> 
>> Have there been any discussions regarding the semantics of _?
>> 
>> struct G { ~this() { writeln("destruct"); } }
>> void main() {
>>      auto _ = G();
>>      writeln("here");
>> }
>> 
>> The DIP currently says this should print first "here" and then 
>> "destruct".
>> 
>> However, as you cannot access the variable later, you most 
>> often want to discard the data right away, i.e. print first 
>> "destruct" and then "here".
>> 
>> I personally find the second interpretation more useful.
>> 
>
> This has not been discussed, but I agree it should be addressed 
> somehow. The main issue is that right now "_" is a valid 
> identifier.

Not sure what the use case is for this, but if you don't need the 
value of the variable, assuming from a function or otherwise. You 
can just not assign it to anything.

struct G { ~this() { writeln("destruct"); } }
void main() {
     G();  // prints "destruct" before "here"
     writeln("here");
}

definitely don't like the idea of changing how scope works. I'd 
rather not the compiler choose to decide whether it does 
something one way or another like that.