1 #ifndef STAN_MATH_PRIM_FUN_IS_INTEGER_HPP
2 #define STAN_MATH_PRIM_FUN_IS_INTEGER_HPP
3 
4 #include <stan/math/prim/meta.hpp>
5 #include <stan/math/prim/fun/floor.hpp>
6 #include <cmath>
7 
8 namespace stan {
9 namespace math {
10 
11 /**
12  * Returns true if the input is an integer and false otherwise.
13  *
14  * @param x Value to test.
15  * @return <code>true</code> if the value is an integer
16  */
17 template <typename T>
is_integer(T x)18 inline bool is_integer(T x) {
19   using std::floor;
20   return floor(x) == x;
21 }
22 
23 }  // namespace math
24 }  // namespace stan
25 
26 #endif
27