LhsEval getInvB_(typename std::enable_if<!HasMember_invB<FluidState>::value, const FluidState&>::type fluidState, unsigned phaseIdx, unsigned pvtRegionIdx) { const auto& rho = fluidState.density(phaseIdx); const auto& Xsolvent = fluidState.massFraction(phaseIdx, FluidSystem::solventComponentIndex(phaseIdx)); return Opm::decay<LhsEval>(rho) *Opm::decay<LhsEval>(Xsolvent) /FluidSystem::referenceDensity(phaseIdx, pvtRegionIdx); }