text: #ifndef STAN_MATH_PRIM_ERR_CHECK_ROW_INDEX_HPP
  #define STAN_MATH_PRIM_ERR_CHECK_ROW_INDEX_HPP
  
  #include <stan/math/prim/meta.hpp>
  #include <stan/math/prim/err/out_of_range.hpp>
  #include <stan/math/prim/fun/Eigen.hpp>
  #include <sstream>
  #include <string>
  
  namespace stan {
  namespace math {
  
  /**
   * Check if the specified index is a valid row of the matrix
   * This check is 1-indexed by default. This behavior can be changed
   * by setting <code>stan::error_index::value</code>.
   * @tparam T Scalar type
   * @tparam R number of rows or Eigen::Dynamic
   * @tparam C number of columns or Eigen::Dynamic
   * @param function Function name (for error messages)
   * @param name Variable name (for error messages)
   * @param y matrix to test
   * @param i row index to check
   * @throw <code>std::out_of_range</code> if the index is out of range.
   */
  template <typename T_y, int R, int C>
  inline void check_row_index(const char* function, const char* name,
                              const Eigen::Matrix<T_y, R, C>& y, size_t i) {
    if (i >= stan::error_index::value
        && i < static_cast<size_t>(y.rows()) + stan::error_index::value) {
      return;
    }
  
    std::stringstream msg;
    msg << " for rows of " << name;
    std::string msg_str(msg.str());
    out_of_range(function, y.rows(), i, msg_str.c_str());
  }
  
  }  // namespace math
  }  // namespace stan
  #endif
  