🔀 merge develop branch and resolve conflicts

include/nlohmann/ordered_map.hpp

@@ -12,7 +12,7 @@ namespace nlohmann
 /// for use within nlohmann::basic_json<ordered_map>
 template <class Key, class T, class IgnoredLess = std::less<Key>,
           class Allocator = std::allocator<std::pair<const Key, T>>>
-struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>
+                  struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>
 {
     using key_type = Key;
     using mapped_type = T;

single_include/nlohmann/json.hpp

@@ -2822,6 +2822,19 @@ uses the standard template types.
 @since version 1.0.0
 */
 using json = basic_json<>;
+
+template<class Key, class T, class IgnoredLess, class Allocator>
+struct ordered_map;
+
+/*!
+@brief ordered JSON class
+
+This type preserves the insertion order of object keys.
+
+@since version 3.9.0
+*/
+using ordered_json = basic_json<nlohmann::ordered_map>;
+
 }  // namespace nlohmann
 
 #endif  // INCLUDE_NLOHMANN_JSON_FWD_HPP_
@@ -16000,6 +16013,79 @@ class serializer
 
 // #include <nlohmann/json_fwd.hpp>
 
+// #include <nlohmann/ordered_map.hpp>
+
+
+#include <functional> // less
+#include <memory> // allocator
+#include <utility> // pair
+#include <vector> // vector
+
+namespace nlohmann
+{
+
+/// ordered_map: a minimal map-like container that preserves insertion order
+/// for use within nlohmann::basic_json<ordered_map>
+template <class Key, class T, class IgnoredLess = std::less<Key>,
+          class Allocator = std::allocator<std::pair<const Key, T>>>
+                  struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>
+{
+    using key_type = Key;
+    using mapped_type = T;
+    using Container = std::vector<std::pair<const Key, T>, Allocator>;
+    using typename Container::iterator;
+    using typename Container::size_type;
+    using typename Container::value_type;
+
+    // Explicit constructors instead of `using Container::Container`
+    // otherwise older compilers choke on it (GCC <= 5.5, xcode <= 9.4)
+    ordered_map(const Allocator& alloc = Allocator()) : Container{alloc} {}
+    template <class It>
+    ordered_map(It first, It last, const Allocator& alloc = Allocator())
+        : Container{first, last, alloc} {}
+    ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
+        : Container{init, alloc} {}
+
+    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return {it, false};
+            }
+        }
+        Container::emplace_back(key, t);
+        return {--this->end(), true};
+    }
+
+    T& operator[](Key&& key)
+    {
+        return emplace(std::move(key), T{}).first->second;
+    }
+
+    size_type erase(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                // Since we cannot move const Keys, re-construct them in place
+                for (auto next = it; ++next != this->end(); ++it)
+                {
+                    it->~value_type(); // Destroy but keep allocation
+                    new (&*it) value_type{std::move(*next)};
+                }
+                Container::pop_back();
+                return 1;
+            }
+        }
+        return 0;
+    }
+};
+
+}  // namespace nlohmann
+
 
 /*!
 @brief namespace for Niels Lohmann
@@ -24662,7 +24748,7 @@ template<>
 inline void swap<nlohmann::json>(nlohmann::json& j1, nlohmann::json& j2) noexcept(
     is_nothrow_move_constructible<nlohmann::json>::value and
     is_nothrow_move_assignable<nlohmann::json>::value
-)
+                              )
 {
     j1.swap(j2);
 }