[Issue 19391] New: [ICE] static array comparison

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19391

          Issue ID: 19391
           Summary: [ICE] static array comparison
           Product: D
           Version: D2
          Hardware: x86
                OS: All
            Status: NEW
          Severity: regression
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: iamthewilsonator at hotmail.com

see this commit[1] which worked around it

[1]:https://github.com/libmir/mir-algorithm/commit/c804962c99467168484dbf084bbe491bcd2da2a7

---
auto slice = iota(2, 3).universal.assumeContiguous;
...
- assert(slice._strides == []); // <<< Crashes
+ static assert(slice._strides.length == 0); // the workaround
---

slice._strides is an alias to the second member of a tuple, which somehow ends
up wrongly having the type const(long[1]) outside of CTFE (since the static
assert passes) which when compared for equality to [] (which is inferred as
long[0]) fails in e2ir.d when DMD tries to optimise the comparison to a memcmp
because the size of the two arrays do not match, tripping an assert[2]
assert(t1.size() == t2.size()); where t1,t2 are the type of the static arrays.

[2]: https://github.com/dlang/dmd/blob/master/src/dmd/e2ir.d#L2436

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