[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 #2 from Dlang Bot <dlang-bot at dlang.rocks> ---
dlang/phobos pull request #8394 "sumtype: work around issue 21975 in isSumType"
was merged into master:

- c47c861646ddbb8bd30be849aee37a6167ab41f3 by Paul Backus:
  sumtype: work around issue 21975 in isSumType

  isSumType!T now evaluates to true instead of false when T is a templated
  struct type that implicitly converts to a SumType via alias this.

https://github.com/dlang/phobos/pull/8394

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