On 4/24/2020 1:24 AM, Walter Bright wrote:
> On 4/23/2020 11:00 PM, Manu wrote:
>> I guess this is the key case you need to solve for:
>>
>> template T(Args...) {}
>> T!(Tup) -> T!(0, 1, 2)
>> T!(Tup)... -> T!0, T!1, T!2
>>
>> And the parallel expansion disambiguation is also critical:
>> T!(Tup, Tup2...)... -> T!(0, 3, 4, 5), T!(1, 3, 4, 5), T!(2, 3, 4, 5)
>>
>> If you can solve those, the rest will probably follow.
>
> Fair enough. Though there needs to be a rationale as to why those two particuler
> cases are needed and critical.
Please keep in mind that the following works today:
void foo(int);
template tuple(T...) { enum tuple = T; }
void test() {
auto t = tuple!(1, 2, 3);
static foreach (i, e; t)
foo(e + i);
}
and generates:
void test() {
foo(1); foo(3); foo(5);
}
static foreach is not an expression, and it's very hard to involve those result calls in some conjunction. Expand that code to || them together... it gets ugly real fast.
I wouldn't have wasted my time writing this DIP and a reference implementation if static foreach was fine.
Find instances of `staticMap` in phobos and/or user code, and show how you can replace them with static foreach, then there's something to talk about.