Hello everyone, I recently designed a JSON library that is suitable to the C++ standard, but I don’t have much experience with using allocators, so I need an allocator expert to help me improve it. Any suggestions are welcome and I hope you like it.

https://storage.nykz.org/proposals/minimal-json/

Here are some use cases:

#include "basic_json.hpp"
#include <string_view>
int main()
{
      /*
          Note: This code is for demonstration purposes only and can be compiled only, not be run.
      */
      // json
      using json = bizwen::json;
      using namespace std::literals;
      json j01{};
      json j02{ j01 };
      // j j03{ nullptr }; deleted
      json j04{ 1. };
      json j05{ true };
      json j06{ 1.f };
      json j07{ 1u };
      json j08{ 1l };
      json j09{ 1ll };
      json j10{ 1ull };
      json j11{ "aaa" };
      auto str = "bbb";
      json j12{ str, str + 3 };
      json j13{ str, 3 };
      json j14{ str };
      json j15{ "bbb"sv };
      // since initializer_list returns a reference to a const object, this method is inefficient
      // json j16{ json::array_type{ json{0}, json{1} } };
      // json j17{ json::object_type{ { "key0"s, json{ 0 } }, { "key1"s, json{ 1 } } } };
      json j16{ json::array{ 0, 1 } };
      json j17{ json::object{"key0"s, 0, "key1"s, 1} };
      json j18{ bizwen::basic_json_node<>{} };
      swap(j17, j18); // adl hidden friend
      j17.swap(j18);
      j17 = j18;
      std::swap(j17, j18);
      json::node_type n{ std::move(j18) };

      // const_slice
      using const_slice = bizwen::const_json_slice;
      const_slice c1;
      c1.empty();
      c1.array();
  c1.string();
      c1.null();
      c1.boolean();
      c1.number();
      c1.object();
      c1.array();
      c1.object();
      c1.integer();
      c1.uinteger();
      c1["key"];
      c1["key"s];
      // requires transparent comparable
      // c1["key"sv];
      c1[1];
      const_slice c2{ j17 };
      c2.swap(c1);
      std::swap(c1, c2);
      const_slice c3{ std::move(j17) };
      const_slice c4 = c3;
      const_slice c5 = std::move(c4);
      c4 = c5;
      c5 = std::move(c4);
      bool b{ c5 };
      bizwen::nulljson_t nj{ c5 };
      json::string_type const& s{ c5 };
      json::array_type const& a{ c5 };
      for (auto const& i : a)
      {
            const_slice item{ i };
      }
      json::object_type const& o{ c5 };
      for (auto const& [k, v] : o)
      {
            const_slice item{ v };
      }
      long long ll{ c5 };
      unsigned long long ull{ c5 };

      // slice
      using slice = bizwen::json_slice;
      slice s1{};
      slice s2{ j17 };
      const_slice c6 = s2;
      std::string str1;
      s2 = str1;
      s2 = std::string{};
      s2 = "aaa";
      s2 = std::string_view{};
      s2 = bizwen::nulljson;
      s2 = true;
      s2 = 1.;
      s2 = 1;
      s2 = 1u;
      s2 = 1ll;
      s2 = 1ull;
  s2 = n;
      s2["key"] = 1;
}