void main() {
	int[int[1]] aa;
	aa[[2]] = 1;
	assert([2] in aa);
}

---

This assertion fails in 2081.1. Is this a bug?

https://dpaste.dzfl.pl/d4c0d4607482

On Sunday, 22 July 2018 at 19:42:45 UTC, Peter Alexander wrote:
> void main() {
> 	int[int[1]] aa;
> 	aa[[2]] = 1;
> 	assert([2] in aa);
> }
>
> ---
>
> This assertion fails in 2081.1. Is this a bug?

Definitely. Looks like `[2]` makes a dynamic array (length + pointer) and `in` reinterprets it as an `int[1]`.

More examples:

----
void main()
{
    int[int[1]] aa = [[2]: 1];
    assert([123, 456] in aa); /* Passes. Shouldn't even compile. */

    size_t[] dynarr = [1, 2, 3];
    string[size_t[2]] aa2 = [[3, cast(size_t) dynarr.ptr]: "Wat."];
    assert(*(dynarr in aa2) == "Wat."); /* Passes. Shouldn't even compile. */
}
----

On Sunday, 22 July 2018 at 19:42:45 UTC, Peter Alexander wrote:
> void main() {
> 	int[int[1]] aa;
> 	aa[[2]] = 1;
> 	assert([2] in aa);
> }
>
> ---
>
> This assertion fails in 2081.1. Is this a bug?
>
> https://dpaste.dzfl.pl/d4c0d4607482

https://issues.dlang.org/show_bug.cgi?id=19112