1 #ifndef STAN_MATH_PRIM_FUN_PLUS_HPP 2 #define STAN_MATH_PRIM_FUN_PLUS_HPP 3 4 #include <stan/math/prim/meta.hpp> 5 6 namespace stan { 7 namespace math { 8 9 /** 10 * Returns the unary plus of the input. 11 * 12 * @tparam T Type of input. 13 * @param x input. 14 * @return result of unary plus of the input. 15 */ 16 template <typename T> plus(T && x)17inline T plus(T&& x) { 18 return std::forward<T>(x); 19 } 20 21 } // namespace math 22 } // namespace stan 23 24 #endif 25