#ifndef STAN_MATH_FWD_SCAL_FUN_LOG10_HPP
#define STAN_MATH_FWD_SCAL_FUN_LOG10_HPP

#include <stan/math/fwd/core.hpp>

#include <stan/math/prim/scal/fun/constants.hpp>

namespace stan {

  namespace math {

    template <typename T>
    inline
    fvar<T>
    log10(const fvar<T>& x) {
      using std::log;
      using std::log10;
      using stan::math::NOT_A_NUMBER;
      if (x.val_ < 0.0)
        return fvar<T>(NOT_A_NUMBER, NOT_A_NUMBER);
      else
        return fvar<T>(log10(x.val_), x.d_ / (x.val_ * stan::math::LOG_10));
    }
  }
}
#endif
