https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103760
Patrick Palka <ppalka at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ppalka at gcc dot gnu.org --- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> --- GCC's behavior appears to be correct here (though perhaps less useful than Clang's). According to wg21.link/temp.deduct.general#9 a lambda expression isn't part of the immediate context, so substitution failure from within the lambda ought to be a hard error, not a SFINAE error. Note that Clang also doesn't reject the first four examples from that paragraph.