fix and update (#677)

include/ylt/standalone/iguana/detail/charconv.h

@@ -3,27 +3,48 @@
 
 #include "dragonbox_to_chars.h"
 #include "fast_float.h"
+#include "iguana/define.h"
 #include "itoa.hpp"
 
 namespace iguana {
 template <typename T>
 struct is_char_type
-    : std::disjunction<std::is_same<T, char>, std::is_same<T, unsigned char>,
-                       std::is_same<T, signed char>, std::is_same<T, wchar_t>,
+    : std::disjunction<std::is_same<T, char>, std::is_same<T, wchar_t>,
                        std::is_same<T, char16_t>, std::is_same<T, char32_t>> {};
 
+inline void *to_chars_float(...) {
+  throw std::runtime_error("not allowed to invoke");
+  return {};
+}
+
+template <typename T, typename Ret = decltype(to_chars_float(
+                          std::declval<T>(), std::declval<char *>()))>
+using return_of_tochars = std::conditional_t<std::is_same_v<Ret, char *>,
+                                             std::true_type, std::false_type>;
+// here std::true_type is used as a type , any other type is also ok.
+using has_to_chars_float = iguana::return_of_tochars<std::true_type>;
+
 namespace detail {
-template <typename U>
+
+// check_number==true: check if the string [first, last) is a legal number
+template <bool check_number = true, typename U>
 std::pair<const char *, std::errc> from_chars(const char *first,
-                                              const char *last,
-                                              U &value) noexcept {
+                                              const char *last, U &value) {
   using T = std::decay_t<U>;
   if constexpr (std::is_floating_point_v<T>) {
     auto [p, ec] = fast_float::from_chars(first, last, value);
+    if constexpr (check_number) {
+      if (p != last || ec != std::errc{})
+        IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
+    }
     return {p, ec};
   }
   else {
     auto [p, ec] = std::from_chars(first, last, value);
+    if constexpr (check_number) {
+      if (p != last || ec != std::errc{})
+        IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
+    }
     return {p, ec};
   }
 }
@@ -33,17 +54,26 @@ template <typename T>
 char *to_chars(char *buffer, T value) noexcept {
   using U = std::decay_t<T>;
   if constexpr (std::is_floating_point_v<U>) {
-    return jkj::dragonbox::to_chars(value, buffer);
+    if constexpr (has_to_chars_float::value) {
+      return static_cast<char *>(to_chars_float(value, buffer));
+    }
+    else {
+      return jkj::dragonbox::to_chars(value, buffer);
+    }
   }
   else if constexpr (std::is_signed_v<U> && (sizeof(U) >= 8)) {
     return xtoa(value, buffer, 10, 1);  // int64_t
   }
   else if constexpr (std::is_unsigned_v<U> && (sizeof(U) >= 8)) {
     return xtoa(value, buffer, 10, 0);  // uint64_t
   }
-  else if constexpr (std::is_integral_v<U> && !is_char_type<U>::value) {
+  else if constexpr (std::is_integral_v<U> && (sizeof(U) > 1)) {
     return itoa_fwd(value, buffer);  // only support more than 2 bytes intergal
   }
+  else if constexpr (!is_char_type<U>::value) {
+    return itoa_fwd(static_cast<int>(value),
+                    buffer);  // only support more than 2 bytes intergal
+  }
   else {
     static_assert(!sizeof(U), "only support arithmetic type except char type");
   }

include/ylt/standalone/iguana/detail/traits.hpp

@@ -67,6 +67,15 @@ template <typename T, typename... Us>
 struct has_type<T, std::tuple<Us...>>
     : std::disjunction<std::is_same<T, Us>...> {};
 
+template <class T>
+struct member_tratis {};
+
+template <class T, class Owner>
+struct member_tratis<T Owner::*> {
+  using owner_type = Owner;
+  using value_type = T;
+};
+
 template <typename T>
 inline constexpr bool is_int64_v =
     std::is_same_v<T, int64_t> || std::is_same_v<T, uint64_t>;

include/ylt/standalone/iguana/json_reader.hpp

@@ -68,8 +68,8 @@ IGUANA_INLINE void from_json_impl(U &value, It &&it, It &&end) {
     if (size == 0)
       IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
     const auto start = &*it;
-    auto [p, ec] = detail::from_chars(start, start + size, value);
-    if (ec != std::errc{})
+    auto [p, ec] = detail::from_chars<false>(start, start + size, value);
+    if (ec != std::errc{} || !can_follow_number(*p))
       IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
     it += (p - &*it);
   }
@@ -82,9 +82,7 @@ IGUANA_INLINE void from_json_impl(U &value, It &&it, It &&end) {
       buffer[i] = *it++;
       ++i;
     }
-    auto [p, ec] = detail::from_chars(buffer, buffer + i, value);
-    if (ec != std::errc{})
-      IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
+    detail::from_chars(buffer, buffer + i, value);
   }
 }
 
@@ -499,6 +497,44 @@ IGUANA_INLINE void skip_object_value(It &&it, It &&end) {
   }
 }
 
+template <typename value_type, typename U, typename It>
+IGUANA_INLINE bool from_json_variant_impl(U &value, It it, It end, It &temp_it,
+                                          It &temp_end) {
+  try {
+    value_type val;
+    from_json_impl(val, it, end);
+    value = val;
+    temp_it = it;
+    temp_end = end;
+    return true;
+  } catch (std::exception &ex) {
+    return false;
+  }
+}
+
+template <typename U, typename It, size_t... Idx>
+IGUANA_INLINE void from_json_variant(U &value, It &it, It &end,
+                                     std::index_sequence<Idx...>) {
+  static_assert(!has_duplicate_type_v<std::remove_reference_t<U>>,
+                "don't allow same type in std::variant");
+  bool r = false;
+  It temp_it = it;
+  It temp_end = end;
+  ((void)(!r && (r = from_json_variant_impl<
+                     variant_element_t<Idx, std::remove_reference_t<U>>>(
+                     value, it, end, temp_it, temp_end),
+                 true)),
+   ...);
+  it = temp_it;
+  end = temp_end;
+}
+
+template <typename U, typename It, std::enable_if_t<variant_v<U>, int> = 0>
+IGUANA_INLINE void from_json_impl(U &value, It &&it, It &&end) {
+  from_json_variant(value, it, end,
+                    std::make_index_sequence<
+                        std::variant_size_v<std::remove_reference_t<U>>>{});
+}
 }  // namespace detail
 
 template <typename T, typename It, std::enable_if_t<refletable_v<T>, int>>
@@ -608,6 +644,31 @@ IGUANA_INLINE void from_json(T &value, const View &view) {
   from_json(value, std::begin(view), std::end(view));
 }
 
+template <
+    auto member,
+    typename Parant = typename member_tratis<decltype(member)>::owner_type,
+    typename T>
+IGUANA_INLINE void from_json(T &value, std::string_view str) {
+  constexpr size_t duplicate_count =
+      iguana::duplicate_count<std::remove_reference_t<Parant>, member>();
+  static_assert(duplicate_count != 1, "the member is not belong to the object");
+  static_assert(duplicate_count == 2, "has duplicate field name");
+
+  constexpr auto name = name_of<member>();
+  constexpr size_t index = index_of<member>();
+  constexpr size_t member_count = member_count_of<member>();
+  str = str.substr(str.find(name) + name.size());
+  size_t pos = str.find(":") + 1;
+  if constexpr (index == member_count - 1) {  // last field
+    str = str.substr(pos, str.find("}") - pos + 1);
+  }
+  else {
+    str = str.substr(pos, str.find(",") - pos);
+  }
+
+  detail::from_json_impl(value.*member, std::begin(str), std::end(str));
+}
+
 template <typename T, typename View,
           std::enable_if_t<json_view_v<View>, int> = 0>
 IGUANA_INLINE void from_json(T &value, const View &view,

include/ylt/standalone/iguana/json_util.hpp

@@ -18,10 +18,7 @@ class numeric_str {
     if (val_.empty())
       IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
     T res;
-    auto [_, ec] =
-        detail::from_chars(val_.data(), val_.data() + val_.size(), res);
-    if (ec != std::errc{})
-      IGUANA_UNLIKELY { throw std::runtime_error("Failed to parse number"); }
+    detail::from_chars(val_.data(), val_.data() + val_.size(), res);
     return res;
   }
 
@@ -214,4 +211,28 @@ IGUANA_INLINE bool is_numeric(char c) noexcept {
   return static_cast<bool>(is_num[static_cast<unsigned int>(c)]);
 }
 
+// '\t' '\r' '\n'  '"' '}' ']' ',' ' '  '\0'
+IGUANA_INLINE bool can_follow_number(char c) noexcept {
+  static constexpr int can_follow_num[256] = {
+      //  0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
+      1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0,  // 0
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 1
+      1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0,  // 2
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 3
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 4
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0,  // 5
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 6
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0,  // 7
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 8
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // 9
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // A
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // B
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // C
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // D
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // E
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0   // F
+  };
+  return static_cast<bool>(can_follow_num[static_cast<unsigned int>(c)]);
+}
+
 }  // namespace iguana

include/ylt/standalone/iguana/json_writer.hpp

@@ -245,6 +245,8 @@ IGUANA_INLINE void to_json_impl(Stream &s, T &&t) {
 template <bool Is_writing_escape, typename Stream, typename T,
           std::enable_if_t<variant_v<T>, int>>
 IGUANA_INLINE void to_json_impl(Stream &s, T &&t) {
+  static_assert(!has_duplicate_type_v<std::remove_reference_t<T>>,
+                "don't allow same type in std::variant");
   std::visit(
       [&s](auto value) {
         to_json_impl<Is_writing_escape>(s, value);

include/ylt/standalone/iguana/reflection.hpp

@@ -910,6 +910,120 @@ constexpr const std::string_view get_name() {
   return M::name();
 }
 
+namespace detail {
+template <typename T, typename U>
+constexpr bool get_index_imple(T ptr, U ele) {
+  if constexpr (std::is_same_v<decltype(ptr), decltype(ele)>) {
+    if (ele == ptr) {
+      return true;
+    }
+    else {
+      return false;
+    }
+  }
+  else {
+    return false;
+  }
+}
+
+template <typename T, typename Tuple, size_t... I>
+constexpr size_t member_index_impl(T ptr, Tuple &tp,
+                                   std::index_sequence<I...>) {
+  bool r = false;
+  size_t index = 0;
+  ((void)(!r && (r = get_index_imple(ptr, std::get<I>(tp)),
+                 !r ? index++ : index, true)),
+   ...);
+  return index;
+}
+
+template <typename T, typename Tuple>
+constexpr size_t member_index(T ptr, Tuple &tp) {
+  return member_index_impl(
+      ptr, tp,
+      std::make_index_sequence<
+          std::tuple_size_v<std::decay_t<decltype(tp)>>>{});
+}
+}  // namespace detail
+
+template <auto member>
+constexpr size_t index_of() {
+  using namespace detail;
+  using T = typename member_tratis<decltype(member)>::owner_type;
+  using M = Reflect_members<T>;
+  constexpr auto tp = M::apply_impl();
+  constexpr size_t Size = std::tuple_size_v<decltype(tp)>;
+  constexpr size_t index = member_index(member, tp);
+  static_assert(index < Size, "out of range");
+  return index;
+}
+
+template <auto... members>
+constexpr std::array<size_t, sizeof...(members)> indexs_of() {
+  return std::array<size_t, sizeof...(members)>{index_of<members>()...};
+}
+
+template <auto member>
+constexpr auto name_of() {
+  using T = typename member_tratis<decltype(member)>::owner_type;
+  using M = Reflect_members<T>;
+  constexpr auto s = M::arr()[index_of<member>()];
+  return std::string_view(s.data(), s.size());
+}
+
+template <auto... members>
+constexpr std::array<std::string_view, sizeof...(members)> names_of() {
+  return std::array<std::string_view, sizeof...(members)>{
+      name_of<members>()...};
+}
+
+template <auto member>
+constexpr auto member_count_of() {
+  using T = typename member_tratis<decltype(member)>::owner_type;
+  using M = Reflect_members<T>;
+  return M::value();
+}
+
+template <typename T, auto member>
+constexpr size_t duplicate_count();
+
+template <auto ptr, typename Member>
+constexpr void check_duplicate(Member member, size_t &index) {
+  using value_type = typename member_tratis<decltype(member)>::value_type;
+
+  if (detail::get_index_imple(ptr, member)) {
+    index++;
+  }
+
+  if constexpr (is_reflection_v<value_type>) {
+    index += iguana::duplicate_count<value_type, ptr>();
+  }
+}
+
+template <typename T, auto member>
+constexpr size_t duplicate_count() {
+  using M = Reflect_members<T>;
+  constexpr auto name = name_of<member>();
+  constexpr auto arr = M::arr();
+
+  constexpr auto tp = M::apply_impl();
+  size_t index = 0;
+  std::apply(
+      [&](auto... ele) {
+        (check_duplicate<member>(ele, index), ...);
+      },
+      tp);
+
+  for (auto &s : arr) {
+    if (s == name) {
+      index++;
+      break;
+    }
+  }
+
+  return index;
+}
+
 template <typename T>
 constexpr const std::string_view get_fields() {
   using M = Reflect_members<T>;