[Issue 21975] is expression ignores implicit conversion of struct via alias this when pattern matching

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=21975

--- Comment #5 from Dlang Bot <dlang-bot at dlang.rocks> ---
dlang/phobos pull request #8397 "Revert "sumtype: work around issue 21975 in
isSumType"" was merged into master:

- 7806947d9447f12062ac0976f9918bec79398449 by Paul Backus:
  Revert "sumtype: work around issue 21975 in isSumType"

  This reverts commit 2de68340ae2a057fd993af7bc2388325e68a9186.

https://github.com/dlang/phobos/pull/8397

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