On 5/7/20 8:33 AM, Ben Jones wrote:> I was doing some metaprogramming
where I wanted to make a slice of a type:
[...]
> alias Ts = AliasSeq!int;
> pragma(msg, Ts);
> alias Tsa = Ts[];
> pragma(msg, Tsa);
> //prints (int), (int)
>
> which confused me until I realized that the [] was slicing the tuple.
> Note, you can add as many [] as you want since it's basically a no-op.
[...]
> Is there any use for this behavior?
Slicing an alias sequence is definitely useful e.g. in recursive templates:
alias car = T[0]; // (head)
alias cdr = T[1..$]; // (tail)
> It seems like it might be worth
> warning like "slicing a tuple is a no-op"
The trouble seems to be when slicing the entire tuple. Even in that
case, printing a warning would not be desired in some situations
ironically in generic code where e.g. T[0..$] may appear, which is the
same as T[].
Ali
