https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95486
--- Comment #3 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> --- Having only the above unconstrained constructor works as expected, so I suppose it's valid. See https://godbolt.org/z/nMysB_. The actual use case doesn't currently have the unconstrained constructor, but does have a constrained constructor and the ICE would prevent usage of the feature.
