On 19/10/16 22:35 +0300, Ville Voutilainen wrote:
Do the operator= SFINAE in the return type for optional, not in the template parameters. * include/std/optional (operator=(_Up&&)): Move SFINAE from template parameters to the return type. (operator=(const optional<_Up>&)): Likewise. (operator=(optional<_Up>&&)): Likewise.
OK.