• d-bugmail puremagic.com (29/29) Dec 02 2019 https://issues.dlang.org/show_bug.cgi?id=20426

d-bugmail puremagic.com writes:

https://issues.dlang.org/show_bug.cgi?id=20426

          Issue ID: 20426
           Summary: doesPointTo with void[N] fails
           Product: D
           Version: D2
          Hardware: All
                OS: All
            Status: NEW
          Severity: normal
          Priority: P1
         Component: phobos
          Assignee: nobody puremagic.com
          Reporter: schveiguy yahoo.com

void[16] n = void;

assert(!doesPointTo(n, n));

gives errors:
/dlang/dmd/linux/bin64/../../src/phobos/std/exception.d(1149): Error: variable
std.exception.doesPointTo!(void[16], void[16], void).doesPointTo.s variables
cannot be of type void
/dlang/dmd/linux/bin64/../../src/phobos/std/exception.d(1149): Error:
expression __r6[__key7] is void and has no value

void[N] technique is a way to provide space for untyped data. doesPointTo
should just ignore it (it's OK for doesPointTo to have false negatives).

The issue is in the handling of static arrays, it foreaches over the elements
and recurses. Of course, there is no element type.

I think the correct fix is simply to return false for void[N].

The end result of not supporting this is that you can't sort types that contain
these items, even if you don't use the void array in the comparison.

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