fixed conformance with C++17, some members of allocator are depricated and should be used via allocator_traits

src/json.hpp

@@ -7944,12 +7944,15 @@ class basic_json
     static T* create(Args&& ... args)
     {
         AllocatorType<T> alloc;
+
+		using AllocatorTraits = std::allocator_traits<AllocatorType<T>>;
+
         auto deleter = [&](T * object)
         {
-            alloc.deallocate(object, 1);
+			AllocatorTraits::deallocate(alloc, object, 1);
         };
-        std::unique_ptr<T, decltype(deleter)> object(alloc.allocate(1), deleter);
+        std::unique_ptr<T, decltype(deleter)> object(AllocatorTraits::allocate(alloc, 1), deleter);
-        alloc.construct(object.get(), std::forward<Args>(args)...);
+		AllocatorTraits::construct(alloc, object.get(), std::forward<Args>(args)...);
         assert(object != nullptr);
         return object.release();
     }
@@ -8937,6 +8940,39 @@ class basic_json
     ~basic_json()
     {
         assert_invariant();
+
+        switch (m_type)
+        {
+            case value_t::object:
+            {
+                AllocatorType<object_t> alloc;
+				std::allocator_traits<decltype(alloc)>::destroy(alloc, m_value.object);
+				std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_value.object, 1);
+                break;
+            }
+
+            case value_t::array:
+            {
+                AllocatorType<array_t> alloc;
+				std::allocator_traits<decltype(alloc)>::destroy(alloc, m_value.array);
+				std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_value.array, 1);
+                break;
+            }
+
+            case value_t::string:
+            {
+                AllocatorType<string_t> alloc;
+				std::allocator_traits<decltype(alloc)>::destroy(alloc, m_value.string);
+				std::allocator_traits<decltype(alloc)>::deallocate(alloc, m_value.string, 1);
+                break;
+            }
+
+            default:
+            {
+                // all other types need no specific destructor
+                break;
+            }
+        }
         m_value.destroy(m_type);
     }