1 #ifndef STAN_MATH_PRIM_FUN_LOGICAL_NEGATION_HPP
2 #define STAN_MATH_PRIM_FUN_LOGICAL_NEGATION_HPP
3 
4 #include <stan/math/prim/meta.hpp>
5 namespace stan {
6 namespace math {
7 
8 /**
9  * The logical negation function which returns one if the input
10  * is equal to zero and zero otherwise.
11  *
12  * @tparam T type of value
13  * @param x value
14  * @return 1 if value is zero and 0 otherwise
15  */
16 template <typename T>
logical_negation(const T & x)17 inline int logical_negation(const T& x) {
18   return x == 0;
19 }
20 
21 }  // namespace math
22 }  // namespace stan
23 #endif
24