Range packing.

include/parselink/msgpack/core/detail/packable_ranges.h

@@ -23,29 +23,78 @@
 
 #include "builtin_packable_types.h"
 #include <ranges>
+#include <tuple>
 
 namespace msgpack {
-namespace detail {} // namespace detail
+namespace detail {
+
+//
+template <typename T>
+concept packable_array = std::ranges::input_range<T>
+                      && builtin_packable<std::ranges::range_value_t<T>>;
 
 template <typename T>
-concept packable_range = std::ranges::input_range<T>
-                      && builtin_packable<std::ranges::range_value_t<T>>;
+concept tuple_like = requires(T t) { typename std::tuple_size<T>::type; };
+
+template <typename T>
+concept key_value_pairlike = requires(T t) {
+    typename std::tuple_size<T>::type;
+} && std::tuple_size_v<T> == 2;
+
+template <typename T>
+concept packable_map =
+        std::ranges::input_range<T>
+        && key_value_pairlike<std::ranges::range_value_t<T>>
+        && builtin_packable<
+                std::tuple_element_t<0, std::ranges::range_value_t<T>>>
+        && builtin_packable<
+                std::tuple_element_t<1, std::ranges::range_value_t<T>>>;
+
+template <typename>
+struct desc_traits;
+
+template <packable_map T>
+struct desc_traits<T> {
+    using type = map_desc;
+};
+
+template <packable_array T>
+struct desc_traits<T> {
+    using type = array_desc;
+};
+
+} // namespace detail
+
+template <typename T>
+concept packable_range = detail::packable_array<T> || detail::packable_map<T>;
 
 template <packable_range T>
 struct builtin_packer<T> : builtin_packer_base {
+    using desc_type = detail::desc_traits<T>::type;
+
     static constexpr std::size_t rep_size(T const& value) {
         return std::ranges::size(value);
     }
 
+    static constexpr auto desc(T const& value) {
+        return desc_type(rep_size(value));
+    }
+
     static constexpr auto marker(T const& value) {
-        array_desc desc(rep_size(value));
-        return builtin_packer<array_desc>::marker(desc);
+        return builtin_packer<desc_type>::marker(desc(value));
     }
 
     static constexpr void pack(T const& value, auto& packer) noexcept {
-        packer.pack(array_desc(rep_size(value)));
-        for (auto const& element : value) {
-            packer.pack(element);
+        packer.pack(desc(value));
+        if constexpr (detail::packable_map<T>) {
+            for (auto const& [key, value] : value) {
+                packer.pack(key);
+                packer.pack(value);
+            }
+        } else {
+            for (auto const& element : value) {
+                packer.pack(element);
+            }
         }
     }
 };

tests/msgpack/BUILD

@@ -76,3 +76,11 @@ cc_binary(
     ],
     deps = ["test_deps"],
 )
+
+cc_binary(
+    name = "code",
+    srcs = [
+        "test_code.cpp",
+    ],
+    deps = ["test_deps"],
+)

tests/msgpack/test_code.cpp

@@ -0,0 +1,17 @@
+#include <array>
+#include <map>
+#include <parselink/msgpack/core/packer.h>
+
+int main(int argc, char** argv) {
+    std::map<int, std::string_view> args{};
+    for (int i = 0; i < argc; ++i) {
+        args.emplace(i, argv[i]);
+    }
+    std::array<std::byte, 500> buff;
+    msgpack::packer packer(buff);
+    packer.pack(args);
+    for (auto b : packer.subspan()) {
+        printf("%c", char(b));
+    }
+    return 0;
+}