https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77825
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |UNCONFIRMED
CC| |jason at gcc dot gnu.org
Ever confirmed|1 |0
--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> ---
This is due to the C++17 constexpr lambda change: previously, we would defer
instantiation of the lambda operator() until EOF, but now we instantiate it
immediately when we call it from y_combinator's operator(). Since we haven't
completed instantiating that function yet, it doesn't have a real return type
yet, so the mutual recursion leads to an error.
