Promotion through assignment?

[Martin v. Loewis]

> Is this non-promotion an issue with gcc (2000612) or an aggressive
> promotion by MSVC (which compiles it fine)? A private Cc: is
> appreciated.

Thanks for your bug report. This is not a bug in the compiler, but in
your code. Copy-construction requires a temporary I object.
Constructing that requires two user-defined conversion operators. That
is not a valid conversion sequence.

If you question this analysis, please discuss it in one of the public
C++ fora first, eg. comp.lang.c++.moderated, or comp.std.c++.

Regards,
Martin