GHypEtaOmega

double beta  = 2;
double _eta  = 3;
double _omega= 4;

auto params  = GHypEtaOmega!double(beta, _eta, _omega);

auto params0 = cast(GHypAlphaDelta!real) params;
auto params1 = cast(GHypChiPsi    !real) params;
auto params2 = cast(GHypEtaOmega  !real) params;
auto params3 = cast(GIGChiPsi     !real) params;
auto params4 = cast(GIGEtaOmega   !real) params;

double alpha = params.alpha;
double delta = params.delta;

double chi   = params.chi;
double psi   = params.psi;

double eta   = params.eta;
double omega = params.omega;