https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126204
--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> --- Created attachment 64998 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64998&action=edit reduced slightly You just need the ?: in a template function. (the auto parameter for lambdas basically turns it into a templte).
