1 #ifndef STAN_MATH_REV_CORE_STD_ISNAN_HPP 2 #define STAN_MATH_REV_CORE_STD_ISNAN_HPP 3 4 #include <stan/math/rev/core/var.hpp> 5 #include <cmath> 6 7 namespace std { 8 9 /** 10 * Checks if the given number is NaN. 11 * 12 * Return <code>true</code> if the value of the 13 * specified variable is not a number. 14 * 15 * @param a Variable to test. 16 * @return <code>true</code> if value is not a number. 17 */ isnan(const stan::math::var & a)18inline bool isnan(const stan::math::var& a) { return isnan(a.val()); } 19 20 } // namespace std 21 #endif 22