[Issue 14457] Algebraic does not allow assignment from subset type

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=14457

--- Comment #1 from github-bugzilla at puremagic.com ---
Commit pushed to master at https://github.com/D-Programming-Language/phobos

https://github.com/D-Programming-Language/phobos/commit/5a9c0bcd6bb60b32eca098fbbaf46746a0cbcfb4
Fixes 14457 (VariantN opAssign subset variant)

Allows a VariantN to be assigned from another VariantN that is a strict
subset.  Implements an opAssign overload that specializes on VariantN
instantations that are not the current VariantN but whose AllowedTypes
are a subset of the current variant's.

Added accompanying unittest.

Fix Issue 14457

--