https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83181
TC <rs2740 at gmail dot com> changed:
What |Removed |Added
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CC| |rs2740 at gmail dot com
--- Comment #1 from TC <rs2740 at gmail dot com> ---
What's happening here is that a deduction failure occurs with the deduction
guide (substitution yields a template non-type parameter of type void whose
argument also can't be deduced) and so it is eliminated from the overload set,
but there's still an implicit guide generated from the constructor and the
deduction is done from that.
[temp.param]/15 proscribes deduction guide templates with a template parameter
that neither is deducible nor has a default argument, so this should be
diagnosed.
