text: //========================================================================================
  // Athena++ astrophysical MHD code
  // Copyright(C) 2014 James M. Stone <jmstone@princeton.edu> and other code contributors
  // Licensed under the 3-clause BSD License, see LICENSE file for details
  //========================================================================================
  //! \file noop.cpp
  //  \brief Implements no-op versions of the general eos functions
  
  // C headers
  
  // C++ headers
  #include <cmath>   // sqrt()
  #include <fstream>
  #include <iostream> // ifstream
  #include <sstream>
  #include <stdexcept> // std::invalid_argument
  #include <string>
  
  // Athena++ headers
  #include "../eos.hpp"
  
  Real EquationOfState::RiemannAsq(Real rho, Real hint) {
    std::stringstream msg;
    msg << "### FATAL ERROR in EquationOfState::RiemannAsq" << std::endl
        << "Function should not be called with current configuration." << std::endl;
    ATHENA_ERROR(msg);
    return -1.0;
  }
  Real EquationOfState::PresFromRhoEg(Real rho, Real egas) {
    std::stringstream msg;
    msg << "### FATAL ERROR in EquationOfState::PresFromRhoEg" << std::endl
        << "Function should not be called with current configuration." << std::endl;
    ATHENA_ERROR(msg);
    return -1.0;
  }
  Real EquationOfState::EgasFromRhoP(Real rho, Real pres) {
    std::stringstream msg;
    msg << "### FATAL ERROR in EquationOfState::EgasFromRhoP" << std::endl
        << "Function should not be called with current configuration." << std::endl;
    ATHENA_ERROR(msg);
    return -1.0;
  }
  Real EquationOfState::AsqFromRhoP(Real rho, Real pres) {
    std::stringstream msg;
    msg << "### FATAL ERROR in EquationOfState::AsqFromRhoP" << std::endl
        << "Function should not be called with current configuration." << std::endl;
    ATHENA_ERROR(msg);
    return -1.0;
  }
  