1 #ifndef STAN_MATH_REV_CORE_STD_ISINF_HPP
2 #define STAN_MATH_REV_CORE_STD_ISINF_HPP
3 
4 #include <stan/math/prim/fun/is_inf.hpp>
5 #include <stan/math/rev/core/var.hpp>
6 
7 namespace std {
8 
9 /**
10  * Return <code>1</code> if the specified argument is positive
11  * infinity or negative infinity and <code>0</code> otherwise.
12  *
13  * @param a Argument.
14  * @return 1 if argument is infinite and 0 otherwise.
15  */
isinf(const stan::math::var & a)16 inline bool isinf(const stan::math::var& a) {
17   return stan::math::is_inf(a.val());
18 }
19 
20 }  // namespace std
21 #endif
22