#ifndef STAN_MATH_PRIM_SCAL_META_INCLUDE_SUMMAND_HPP
#define STAN_MATH_PRIM_SCAL_META_INCLUDE_SUMMAND_HPP

#include <stan/math/prim/scal/meta/is_constant.hpp>
#include <stan/math/prim/scal/meta/scalar_type.hpp>
#include <boost/math/tools/promotion.hpp>

namespace stan {
namespace math {

/**
 * Template metaprogram to calculate whether a summand
 * needs to be included in a proportional (log) probability
 * calculation.  For usage, the first boolean parameter
 * should be set to <code>true</code> if calculating
 * a term up to proportionality.  Other type parameters
 * should be included for all of the types of variables
 * in a term.
 *
 * The <code>value</code> enum will be <code>true</code> if the
 * <code>propto</code> parameter is <code>false</code> or if any
 * of the other template arguments are not constants as defined by
 * <code>stan::is_constant<T></code>.

 * @tparam propto <code>true</code> if calculating up to a
 * proportionality constant.
 * @tparam T1 First
 */
template <bool propto, typename T1 = double, typename T2 = double,
          typename T3 = double, typename T4 = double, typename T5 = double,
          typename T6 = double, typename T7 = double, typename T8 = double,
          typename T9 = double, typename T10 = double>
struct include_summand {
  /**
   * <code>true</code> if a term with the specified propto
   * value and subterm types should be included in a proportionality
   * calculation.
   */
  enum {
    value
    = (!propto || !stan::is_constant<typename scalar_type<T1>::type>::value
       || !stan::is_constant<typename scalar_type<T2>::type>::value
       || !stan::is_constant<typename scalar_type<T3>::type>::value
       || !stan::is_constant<typename scalar_type<T4>::type>::value
       || !stan::is_constant<typename scalar_type<T5>::type>::value
       || !stan::is_constant<typename scalar_type<T6>::type>::value
       || !stan::is_constant<typename scalar_type<T7>::type>::value
       || !stan::is_constant<typename scalar_type<T8>::type>::value
       || !stan::is_constant<typename scalar_type<T9>::type>::value
       || !stan::is_constant<typename scalar_type<T10>::type>::value)
  };
};

}  // namespace math

}  // namespace stan

#endif
