Add map-like helpers

stan/math/prim/err/check_consistent_sizes.hpp

@@ -1,8 +1,10 @@
 #ifndef STAN_MATH_PRIM_ERR_CHECK_CONSISTENT_SIZES_HPP
 #define STAN_MATH_PRIM_ERR_CHECK_CONSISTENT_SIZES_HPP
 
+#include <stan/math/prim/err/check_matching_sizes.hpp>
 #include <stan/math/prim/err/invalid_argument.hpp>
 #include <stan/math/prim/fun/size.hpp>
+#include <stan/math/prim/meta/is_container.hpp>
 #include <stan/math/prim/meta/require_generics.hpp>
 #include <algorithm>
 #include <sstream>
@@ -66,6 +68,34 @@ inline void check_consistent_sizes(const char* function, const char* name1,
   }
 }
 
+/**
+ * Check that the unnamed container inputs have the same size. Inputs are
+ * labeled `arg1`, `arg2`, and so on in error messages.
+ *
+ * @tparam T type of the first input
+ * @tparam Types types of the remaining inputs
+ * @param function function name (for error messages)
+ * @param x first input
+ * @param xs remaining inputs
+ * @throw `invalid_argument` if sizes are inconsistent
+ */
+template <typename T, typename... Types,
+          require_all_container_t<T, Types...>* = nullptr>
+inline void check_consistent_sizes(const char* function, T&& x, Types&&... xs) {
+  std::size_t arg_idx = 2;
+  (
+      [&](const auto& y) {
+        if (x.size() != y.size()) {
+          [&]() STAN_COLD_PATH {
+            const std::string name = "arg" + std::to_string(arg_idx);
+            check_matching_sizes(function, "arg1", x, name.c_str(), y);
+          }();
+        }
+        ++arg_idx;
+      }(xs),
+      ...);
+}
+
 }  // namespace math
 }  // namespace stan
 #endif

stan/math/prim/err/check_matching_dims.hpp

@@ -155,6 +155,35 @@ inline void check_matching_dims(const char* function, const char* name1,
   check_matching_dims(function, name1, y1, name2, y2);
 }
 
+/**
+ * Check that the unnamed Eigen inputs have the same dimensions. Inputs are
+ * labeled `arg1`, `arg2`, and so on in error messages.
+ *
+ * @tparam T type of the first input
+ * @tparam Types types of the remaining inputs
+ * @param function function name (for error messages)
+ * @param x first input
+ * @param xs remaining inputs
+ * @throw `invalid_argument` if dimensions do not match
+ */
+template <typename T, typename... Types,
+          require_all_eigen_t<T, Types...>* = nullptr>
+inline void check_matching_dims(const char* function, const T& x,
+                                const Types&... xs) {
+  std::size_t arg_idx = 2;
+  (
+      [&](const auto& y) {
+        if (x.rows() != y.rows() || x.cols() != y.cols()) {
+          [&]() STAN_COLD_PATH {
+            const std::string name = "arg" + std::to_string(arg_idx);
+            check_matching_dims(function, "arg1", x, name.c_str(), y);
+          }();
+        }
+        ++arg_idx;
+      }(xs),
+      ...);
+}
+
 }  // namespace math
 }  // namespace stan
 #endif

stan/math/prim/functor.hpp

@@ -23,6 +23,7 @@
 #include <stan/math/prim/functor/ode_ckrk.hpp>
 #include <stan/math/prim/functor/ode_rk45.hpp>
 #include <stan/math/prim/functor/ode_store_sensitivities.hpp>
+#include <stan/math/prim/functor/map.hpp>
 #include <stan/math/prim/functor/map_if.hpp>
 #include <stan/math/prim/functor/map_rect.hpp>
 #include <stan/math/prim/functor/map_rect_combine.hpp>