void main(){
int[3] arr = [1, 2, 3,];
}
Is the extra comma legal or is it not flagged as error because of a compiler bug? I have many mixins that generate arrays with the extra comma at the end. I would like to know if I should taken the time to remove them.
even this compiles without errors:
void main(){
int[3] arr = [1, 2, 3,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,];
}
I believe it's legal in order to allow for templates (or even mixins) to work in a generic manner:
template Foo(T) { } //What if Foo is empty like this?
auto arr = [1, 2, Foo!(int), Foo!(long)];
// [1, 2, , ]
It makes templates much easier to work with, so that you don't have to special-case against special outputs.
A more realistic example:
template Iota(size_t start, size_t end) //All integers in range [start, end)
{
static if (start < end)
alias TypeTuple!(start, Iota!(start + 1, end)) Iota;
else
alias TypeTuple!() Iota;
}
auto arr1 = [-10, Iota!(0, 3)]; // arr is now [-10, 0, 1, 2]
auto arr2 = [-10, Iota!(a, b)]; // arr is now [-10, a .. b]
Now what happens if a is equal to b? Then arr2 decays to [-10, ].