commit c6e1e260183dfd6f783bfe4690e2528e5bf7e509
author Niels Lohmann <mail@nlohmann.me> Fri Nov 15 07:02:12 2019 +0100
committer GitHub <noreply@github.com> Fri Nov 15 07:02:12 2019 +0100
tree c63e459620f1e39eb3bc6be689646c0647a78b86
parent be61ad147000be4802173d0d118fd1b8109b4668
parent efa13c663d8098a453c6e46769ee05165ecf47f9

Merge pull request #1838 from nickaein/fix-quadratic-destruction

Fix quadratic destruction complexity

include/nlohmann/json.hpp

diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp
index 5d07b8f..eecff7f 100644
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -1010,7 +1010,6 @@
             else if (t == value_t::object)
             {
                 stack.reserve(object->size());
-
                 for (auto&& it : *object)
                 {
                     stack.push_back(std::move(it.second));
@@ -1027,8 +1026,6 @@
                 // its children to the stack to be processed later
                 if (current_item.is_array())
                 {
-                    stack.reserve(stack.size() + current_item.m_value.array->size());
-
                     std::move(current_item.m_value.array->begin(), current_item.m_value.array->end(),
                               std::back_inserter(stack));
 
@@ -1036,15 +1033,16 @@
                 }
                 else if (current_item.is_object())
                 {
-                    stack.reserve(stack.size() + current_item.m_value.object->size());
-
                     for (auto&& it : *current_item.m_value.object)
                     {
                         stack.push_back(std::move(it.second));
                     }
+
+                    current_item.m_value.object->clear();
                 }
 
-                // current_item is destroyed here
+                // it's now safe that current_item get destructed
+                // since it doesn't have any children
             }
 
             switch (t)

single_include/nlohmann/json.hpp

diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 726a963..f9be0b4 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -15553,7 +15553,6 @@
             else if (t == value_t::object)
             {
                 stack.reserve(object->size());
-
                 for (auto&& it : *object)
                 {
                     stack.push_back(std::move(it.second));
@@ -15570,8 +15569,6 @@
                 // its children to the stack to be processed later
                 if (current_item.is_array())
                 {
-                    stack.reserve(stack.size() + current_item.m_value.array->size());
-
                     std::move(current_item.m_value.array->begin(), current_item.m_value.array->end(),
                               std::back_inserter(stack));
 
@@ -15579,15 +15576,16 @@
                 }
                 else if (current_item.is_object())
                 {
-                    stack.reserve(stack.size() + current_item.m_value.object->size());
-
                     for (auto&& it : *current_item.m_value.object)
                     {
                         stack.push_back(std::move(it.second));
                     }
+
+                    current_item.m_value.object->clear();
                 }
 
-                // current_item is destroyed here
+                // it's now safe that current_item get destructed
+                // since it doesn't have any children
             }
 
             switch (t)