From e440a7c52f23e968d5767f8d04c08ec830efb4ed Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Tue, 6 Feb 2018 21:45:58 -0800
Subject: [PATCH] Convert some copy constructors to move constructors in
 query.cc

---
 src/query.cc     | 14 +++++++-------
 src/serializer.h |  6 +++---
 src/utils.h      |  4 ++--
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/query.cc b/src/query.cc
index 6b4d4b63..efb1ba05 100644
--- a/src/query.cc
+++ b/src/query.cc
@@ -100,7 +100,7 @@ optional<QueryVar::Def> ToQuery(const IdMap& id_map, const IndexVar::Def& var) {
 template <typename TId, typename TValue>
 void AddMergeableRange(
     std::vector<MergeableUpdate<TId, TValue>>* dest,
-    const std::vector<MergeableUpdate<TId, TValue>>& source) {
+    std::vector<MergeableUpdate<TId, TValue>>&& source) {
   // TODO: Consider caching the lookup table. It can probably save even more
   // time at the cost of some additional memory.
 
@@ -111,13 +111,13 @@ void AddMergeableRange(
     id_to_index[(*dest)[i].id] = i;
 
   // Add entries. Try to add them to an existing entry.
-  for (const auto& entry : source) {
+  for (auto& entry : source) {
     auto it = id_to_index.find(entry.id);
     if (it != id_to_index.end()) {
-      AddRange(&(*dest)[it->second].to_add, entry.to_add);
-      AddRange(&(*dest)[it->second].to_remove, entry.to_remove);
+      AddRange(&(*dest)[it->second].to_add, std::move(entry.to_add));
+      AddRange(&(*dest)[it->second].to_remove, std::move(entry.to_remove));
     } else {
-      dest->push_back(entry);
+      dest->push_back(std::move(entry));
     }
   }
 }
@@ -664,8 +664,8 @@ IndexUpdate::IndexUpdate(const IdMap& previous_id_map,
 
 // This function runs on an indexer thread.
 void IndexUpdate::Merge(IndexUpdate&& update) {
-#define INDEX_UPDATE_APPEND(name) AddRange(&name, update.name);
-#define INDEX_UPDATE_MERGE(name) AddMergeableRange(&name, update.name);
+#define INDEX_UPDATE_APPEND(name) AddRange(&name, std::move(update.name));
+#define INDEX_UPDATE_MERGE(name) AddMergeableRange(&name, std::move(update.name));
 
   INDEX_UPDATE_APPEND(files_removed);
   INDEX_UPDATE_APPEND(files_def_update);
diff --git a/src/serializer.h b/src/serializer.h
index 714b6c10..3a0a3dcd 100644
--- a/src/serializer.h
+++ b/src/serializer.h
@@ -185,7 +185,7 @@ void Reflect(Reader& visitor, optional<T>& value) {
   }
   T real_value;
   Reflect(visitor, real_value);
-  value = real_value;
+  value = std::move(real_value);
 }
 template <typename T>
 void Reflect(Writer& visitor, optional<T>& value) {
@@ -204,7 +204,7 @@ void Reflect(Reader& visitor, Maybe<T>& value) {
   }
   T real_value;
   Reflect(visitor, real_value);
-  value = real_value;
+  value = std::move(real_value);
 }
 template <typename T>
 void Reflect(Writer& visitor, Maybe<T>& value) {
@@ -254,7 +254,7 @@ struct ReflectVariant {
   ReflectTag(Reader& visitor, std::variant<Ts...>& value) {
     T a;
     Reflect(visitor, a);
-    value = a;
+    value = std::move(a);
   }
   // This SFINAE overload is used to prevent compile error. value = a; is not
   // allowed if T does not appear in Ts...
diff --git a/src/utils.h b/src/utils.h
index 5b985ba6..aa27e721 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -137,8 +137,8 @@ void AddRange(std::vector<T>* dest, const std::vector<T>& to_add) {
 
 template <typename T>
 void AddRange(std::vector<T>* dest, std::vector<T>&& to_add) {
-  dest->push_back(dest->end(), std::make_move_iterator(to_add.begin()),
-                  std::make_move_iterator(to_add.end()));
+  dest->insert(dest->end(), std::make_move_iterator(to_add.begin()),
+               std::make_move_iterator(to_add.end()));
 }
 
 template <typename T>