1 #ifndef STAN_MATH_PRIM_FUN_ROUND_HPP
2 #define STAN_MATH_PRIM_FUN_ROUND_HPP
3 
4 #include <stan/math/prim/meta.hpp>
5 #include <stan/math/prim/fun/Eigen.hpp>
6 #include <stan/math/prim/functor/apply_scalar_unary.hpp>
7 #include <stan/math/prim/functor/apply_vector_unary.hpp>
8 #include <cmath>
9 
10 namespace stan {
11 namespace math {
12 
13 /**
14  * Structure to wrap `round()` so it can be vectorized.
15  *
16  * @tparam T type of argument
17  * @param x argument variable
18  * @return Rounded value of x.
19  */
20 struct round_fun {
21   template <typename T>
funstan::math::round_fun22   static inline T fun(const T& x) {
23     using std::round;
24     return round(x);
25   }
26 };
27 
28 /**
29  * Vectorized version of `round()`.
30  *
31  * @tparam Container type of container
32  * @param x container
33  * @return Rounded value of each value in x.
34  */
35 template <typename Container,
36           require_not_container_st<std::is_arithmetic, Container>* = nullptr,
37           require_all_not_nonscalar_prim_or_rev_kernel_expression_t<
38               Container>* = nullptr>
round(const Container & x)39 inline auto round(const Container& x) {
40   return apply_scalar_unary<round_fun, Container>::apply(x);
41 }
42 
43 /**
44  * Version of `round()` that accepts std::vectors, Eigen Matrix/Array objects
45  *  or expressions, and containers of these.
46  *
47  * @tparam Container Type of x
48  * @param x Container
49  * @return Rounded value of each value in x.
50  */
51 template <typename Container,
52           require_container_st<std::is_arithmetic, Container>* = nullptr>
round(const Container & x)53 inline auto round(const Container& x) {
54   return apply_vector_unary<Container>::apply(
55       x, [](const auto& v) { return v.array().round(); });
56 }
57 
58 }  // namespace math
59 }  // namespace stan
60 
61 #endif
62