support custom reflection struct

.github/workflows/clang-format.yml

@@ -2,9 +2,9 @@ name: Clang Format Diff
 
 on:
   push:
-    branches: [ master]
+    branches: [ master, struct_pb ]
   pull_request:
-    branches: [ master]
+    branches: [ master, struct_pb ]
 
 jobs:
   build:

.github/workflows/linux-clang.yml

@@ -2,9 +2,9 @@ name: Ubuntu (clang)
 
 on:
   push:
-    branches: [ master]
+    branches: [ master, struct_pb ]
   pull_request:
-    branches: [ master]
+    branches: [ master, struct_pb ]
 
 jobs:
   build:

.github/workflows/linux-gcc.yml

@@ -2,9 +2,9 @@ name: Ubuntu (gcc)
 
 on:
   push:
-    branches: [ master]
+    branches: [ master, struct_pb ]
   pull_request:
-    branches: [ master]
+    branches: [ master, struct_pb ]
 
 jobs:
   ubuntu_gcc:

.github/workflows/mac.yml

@@ -2,9 +2,9 @@ name:  macOS Monterey 12
 
 on:
   push:
-    branches: [ master]
+    branches: [ master, struct_pb ]
   pull_request:
-    branches: [ master]
+    branches: [ master, struct_pb ]
 
 jobs:
   build:

.github/workflows/windows.yml

@@ -1,10 +1,10 @@
 name: Windows Server 2022
 
-on: 
+on:
   push:
-    branches: [ master]
+    branches: [ master, struct_pb ]
   pull_request:
-    branches: [ master]
+    branches: [ master, struct_pb ]
 
 jobs:
   build:

iguana/pb_util.hpp

@@ -328,12 +328,9 @@ constexpr inline size_t variant_intergal_size(U value) {
   }
 }
 
-template <typename T, typename F>
-constexpr void for_each_tp(T&& t, F&& f) {
-  constexpr auto tp = get_members<T, false>();
-  using Tuple = decltype(tp);
-  for_each(tp, std::forward<F>(f),
-           std::make_index_sequence<std::tuple_size_v<Tuple>>{});
+template <typename F, size_t... I>
+constexpr void for_each_n(F&& f, std::index_sequence<I...>) {
+  (std::forward<F>(f)(std::integral_constant<size_t, I>{}), ...);
 }
 
 // cache the size of reflection type
@@ -343,23 +340,26 @@ auto& get_set_size_cache(T& t) {
   return cache[reinterpret_cast<size_t>(&t)];
 }
 
-// TODO: support user-defined struct
 // returns size = key_size + optional(len_size) + len
 // when key_size == 0, return len
 template <size_t key_size = 0, typename T>
 inline size_t pb_item_size(T&& t) {
   using value_type = std::remove_const_t<std::remove_reference_t<T>>;
-  if constexpr (is_reflection_v<value_type>) {
+  if constexpr (is_reflection_v<value_type> ||
+                is_custom_reflection_v<value_type>) {
     size_t len = 0;
-    for_each_tp(t, [&len, &t](const auto& val, auto i) {
-      constexpr static auto tp = get_members_impl<T>();
-      constexpr auto value = std::get<decltype(i)::value>(tp);
-      using U = typename std::decay_t<decltype(value)>::value_type;
-      constexpr uint32_t sub_key =
-          (value.field_no << 3) | static_cast<uint32_t>(get_wire_type<U>());
-      constexpr auto sub_keysize = variant_uint32_size_constexpr(sub_key);
-      len += pb_item_size<sub_keysize>(value.value(t));
-    });
+    constexpr auto tp = get_members_impl<value_type>();
+    constexpr size_t SIZE = std::tuple_size_v<std::decay_t<decltype(tp)>>;
+    for_each_n(
+        [&len, &t, &tp](auto i) {
+          constexpr auto value = std::get<decltype(i)::value>(tp);
+          using U = typename std::decay_t<decltype(value)>::value_type;
+          constexpr uint32_t sub_key =
+              (value.field_no << 3) | static_cast<uint32_t>(get_wire_type<U>());
+          constexpr auto sub_keysize = variant_uint32_size_constexpr(sub_key);
+          len += pb_item_size<sub_keysize>(value.value(t));
+        },
+        std::make_index_sequence<SIZE>{});
     get_set_size_cache(t) = len;
     if constexpr (key_size == 0) {
       return len;

iguana/pb_writer.hpp

@@ -50,7 +50,7 @@ inline void encode_pair_value(V&& val, Stream& out, size_t size) {
 template <uint32_t key, typename Type, typename Stream>
 inline void to_pb_impl(Type& t, Stream& out) {
   using T = std::remove_const_t<std::remove_reference_t<Type>>;
-  if constexpr (is_reflection_v<T>) {
+  if constexpr (is_reflection_v<T> || is_custom_reflection_v<T>) {
     // TODO: improve the key serialize
     auto len = pb_load_size(t);
     if (len == 0) {
@@ -60,14 +60,18 @@ inline void to_pb_impl(Type& t, Stream& out) {
       serialize_varint(key, out);
       serialize_varint(len, out);
     }
-    for_each_tp(t, [&t, &out](const auto& val, auto i) {
-      constexpr static auto tp = get_members_impl<T>();
-      constexpr auto value = std::get<decltype(i)::value>(tp);
-      using U = typename std::decay_t<decltype(value)>::value_type;
-      constexpr uint32_t sub_key =
-          (value.field_no << 3) | static_cast<uint32_t>(get_wire_type<U>());
-      to_pb_impl<sub_key>(value.value(t), out);
-    });
+    // TODO: constexpr static auto tp
+    constexpr auto tp = get_members_impl<T>();
+    constexpr size_t SIZE = std::tuple_size_v<std::decay_t<decltype(tp)>>;
+    for_each_n(
+        [&t, &out, &tp](auto i) {
+          constexpr auto value = std::get<decltype(i)::value>(tp);
+          using U = typename std::decay_t<decltype(value)>::value_type;
+          constexpr uint32_t sub_key =
+              (value.field_no << 3) | static_cast<uint32_t>(get_wire_type<U>());
+          to_pb_impl<sub_key>(value.value(t), out);
+        },
+        std::make_index_sequence<SIZE>{});
   }
   else if constexpr (is_sequence_container<T>::value) {
     // TODO support std::array

iguana/reflection.hpp

@@ -737,7 +737,18 @@ template <typename T, typename = void>
 struct is_custom_reflection : std::false_type {};
 
 template <typename T>
-struct is_custom_reflection<T, std::void_t<decltype(get_members_impl(std::declval<T*>()))>> : std::true_type {};
+struct is_custom_reflection<
+    T, std::void_t<decltype(get_members_impl(std::declval<T *>()))>>
+    : std::true_type {};
+
+template <typename T, typename = void>
+struct is_reflection : std::false_type {};
+
+template <typename T>
+inline constexpr bool is_reflection_v = is_reflection<T>::value;
+
+template <typename T>
+inline constexpr bool is_custom_reflection_v = is_custom_reflection<T>::value;
 
 struct field_helper {
   template <typename T, typename U, size_t... I>
@@ -749,10 +760,16 @@ struct field_helper {
 
 template <typename T>
 constexpr inline auto get_members_impl() {
-  using reflect_members = decltype(iguana_reflect_type(std::declval<T>()));
-  using Tuple = decltype(reflect_members::apply_impl());
-  return field_helper{}(reflect_members::apply_impl(), reflect_members::arr(),
-                        std::make_index_sequence<std::tuple_size_v<Tuple>>{});
+  if constexpr (is_reflection_v<T>) {
+    using reflect_members = decltype(iguana_reflect_type(std::declval<T>()));
+    using Tuple = decltype(reflect_members::apply_impl());
+    return field_helper{}(reflect_members::apply_impl(), reflect_members::arr(),
+                          std::make_index_sequence<std::tuple_size_v<Tuple>>{});
+  }
+  else if constexpr (is_custom_reflection_v<T>) {
+    using U = std::remove_const_t<std::remove_reference_t<T>>;
+    return get_members_impl((U *)nullptr);
+  }
 }
 
 template <typename T, size_t Size>
@@ -766,9 +783,6 @@ struct member_helper {
   }
 };
 
-template <typename T, typename = void>
-struct is_reflection : std::false_type {};
-
 template <typename T, bool is_return_map = true>
 constexpr inline auto get_members() {
   if constexpr (is_reflection<T>::value) {
@@ -784,7 +798,7 @@ constexpr inline auto get_members() {
       return get_members_impl<T>();
     }
   }
-  else if constexpr (is_custom_reflection<T>::value) {
+  else if constexpr (is_custom_reflection_v<T>) {
     using U = std::remove_const_t<std::remove_reference_t<T>>;
     constexpr size_t Size = iguana_member_count((U *)nullptr);
     using value_type = typename user_field_type_t<decltype(get_members_impl(
@@ -928,12 +942,6 @@ inline auto iguana_reflect_type(const T &t) {
   }
 }
 
-template <typename T>
-inline constexpr bool is_reflection_v = is_reflection<T>::value;
-
-template <typename T>
-inline constexpr bool is_custom_reflection_v = is_custom_reflection<T>::value;
-
 template <std::size_t index, template <typename...> typename Condition,
           typename Tuple, typename Owner>
 constexpr int element_index_helper() {

test/test_pb.cpp

@@ -18,7 +18,7 @@ struct inner_struct {
   int z;
 };
 
-inline auto get_members_impl(inner_struct *) {
+constexpr inline auto get_members_impl(inner_struct *) {
   return std::make_tuple(iguana::field_t{&inner_struct::x, 7, "a"},
                          iguana::field_t{&inner_struct::y, 9, "b"},
                          iguana::field_t{&inner_struct::z, 12, "c"});
@@ -173,19 +173,19 @@ struct numer_st {
 REFLECTION(numer_st, a, b, c);
 
 TEST_CASE("test struct_pb") {
-  // {
-  //   my_space::inner_struct inner{41, 42, 43};
-
-  //   std::string str;
-  //   iguana::to_pb(inner, str);
-  //   // CHECK(str.size() == iguana::detail::pb_item_size(inner));
-
-  //   my_space::inner_struct inner1;
-  //   iguana::from_pb(inner1, str);
-  //   CHECK(inner.x == inner1.x);
-  //   CHECK(inner.y == inner1.y);
-  //   CHECK(inner.z == inner1.z);
-  // }
+  {
+    my_space::inner_struct inner{41, 42, 43};
+
+    std::string str;
+    iguana::to_pb(inner, str);
+    CHECK(str.size() == iguana::detail::pb_item_size(inner));
+
+    my_space::inner_struct inner1;
+    iguana::from_pb(inner1, str);
+    CHECK(inner.x == inner1.x);
+    CHECK(inner.y == inner1.y);
+    CHECK(inner.z == inner1.z);
+  }
 
   {
     test_pb_st1 st1{41, {42}, {43}};