unspecified TODO TODO boost::variant< unspecified > Exposes a recursive variant whose bounded types are the elements of the given type sequence. variant< unspecified > TODO type has behavior equivalent in every respect to make_recursive_variant< Sequence[0], Sequence[1], ... >::type (where Sequence[i] denotes the i-th element of Sequence), except that no upper limit is imposed on the number of types. Notes: Sequence must meet the requirements of the MPL Sequence concept. Due to standard conformance problems in several compilers, make_recursive_variant_over may not be supported on your compiler. See BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT for more information.