1 #ifndef STAN_MATH_REV_FUN_VALUE_OF_HPP 2 #define STAN_MATH_REV_FUN_VALUE_OF_HPP 3 4 #include <stan/math/rev/meta.hpp> 5 #include <stan/math/rev/core.hpp> 6 7 namespace stan { 8 namespace math { 9 10 /** 11 * Return the value of the specified variable. 12 * 13 * <p>This function is used internally by autodiff functions along 14 * with <code>value_of(T x)</code> to extract the 15 * <code>double</code> value of either a scalar or an autodiff 16 * variable. This function will be called when the argument is a 17 * <code>var</code> even if the function is not 18 * referred to by namespace because of argument-dependent lookup. 19 * 20 * @param v Variable. 21 * @return Value of variable. 22 */ 23 template <typename T> value_of(const var_value<T> & v)24inline auto& value_of(const var_value<T>& v) { 25 return v.vi_->val_; 26 } 27 28 } // namespace math 29 } // namespace stan 30 #endif 31