#ifndef STAN_MATH_MIX_FUNCTOR_DERIVATIVE_HPP
#define STAN_MATH_MIX_FUNCTOR_DERIVATIVE_HPP

#include <stan/math/fwd/core.hpp>
#include <stan/math/prim/fun/Eigen.hpp>
#include <stan/math/rev/core.hpp>
#include <vector>

namespace stan {
namespace math {

/**
 * Return the derivative of the specified univariate function at
 * the specified argument.
 *
 * @tparam T Argument type
 * @tparam F Function type
 * @param[in] f Function
 * @param[in] x Argument
 * @param[out] fx Value of function applied to argument
 * @param[out] dfx_dx Value of derivative
 */
template <typename T, typename F>
void derivative(const F& f, const T& x, T& fx, T& dfx_dx) {
  fvar<T> x_fvar = fvar<T>(x, 1.0);
  fvar<T> fx_fvar = f(x_fvar);
  fx = fx_fvar.val_;
  dfx_dx = fx_fvar.d_;
}

}  // namespace math
}  // namespace stan
#endif
