From c016c30f0f2604e78140e358ba1b8c55a8be5a7f Mon Sep 17 00:00:00 2001
From: Dave Cridland <dave+trippy@cridland.net>
Date: Thu, 18 Jul 2024 14:07:11 +0100
Subject: [PATCH] Avoid temporary when setting value via *_element

---
 rapidxml.hpp           | 47 +++++++++++++++++-------------------------
 test/manipulations.cpp |  5 +++--
 2 files changed, 22 insertions(+), 30 deletions(-)

diff --git a/rapidxml.hpp b/rapidxml.hpp
index eff79a8..ad91a47 100644
--- a/rapidxml.hpp
+++ b/rapidxml.hpp
@@ -1222,7 +1222,7 @@ namespace rapidxml
         }
         optional_ptr<xml_node<Ch>> allocate_element(std::initializer_list<const Ch *> const & clark_name, view_type const & value) {
             auto child = allocate_element(clark_name);
-            child->value(value);
+            if (!value.empty()) child->value(value);
             return child;
         }
     public:
@@ -1252,19 +1252,16 @@ namespace rapidxml
         auto prepend_node(optional_ptr<xml_node<Ch>> ptr) {
             return prepend_node(ptr.get());
         }
-        template<typename... Args>
-        auto prepend_element(view_type const & v, Args... args) {
-            auto child = allocate_element(v, args...);
+        auto prepend_element(view_type const & v, view_type const & value = {}) {
+            auto child = allocate_element(v, value);
             return prepend_node(child);
         }
-        template<typename... Args>
-        auto prepend_element(std::tuple<view_type, view_type> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto prepend_element(std::tuple<view_type, view_type> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return prepend_node(child);
         }
-        template<typename... Args>
-        auto prepend_element(std::initializer_list<const Ch *> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto prepend_element(std::initializer_list<const Ch *> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return prepend_node(child);
         }
 
@@ -1293,19 +1290,16 @@ namespace rapidxml
         optional_ptr<xml_node<Ch>> append_node(optional_ptr<xml_node<Ch>> ptr) {
             return append_node(ptr.get());
         }
-        template<typename... Args>
-        auto append_element(view_type const & v, Args... args) {
-            auto child = allocate_element(v, args...);
+        auto append_element(view_type const & v, view_type const & value = {}) {
+            auto child = allocate_element(v, value);
             return append_node(child);
         }
-        template<typename... Args>
-        auto append_element(std::tuple<view_type, view_type> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto append_element(std::tuple<view_type, view_type> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return append_node(child);
         }
-        template<typename... Args>
-        auto append_element(std::initializer_list<const Ch *> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto append_element(std::initializer_list<const Ch *> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return append_node(child);
         }
 
@@ -1335,19 +1329,16 @@ namespace rapidxml
         auto insert_node(optional_ptr<xml_node<Ch>> where, optional_ptr<xml_node<Ch>> ptr) {
             return insert_node(where.ptr(), ptr.ptr());
         }
-        template<typename... Args>
-        auto insert_element(optional_ptr<xml_node<Ch>> where, view_type const & v, Args... args) {
-            auto child = allocate_element(v, args...);
+        auto insert_element(optional_ptr<xml_node<Ch>> where, view_type const & v, view_type const & value = {}) {
+            auto child = allocate_element(v, value);
             return insert_node(where, child);
         }
-        template<typename... Args>
-        auto insert_element(optional_ptr<xml_node<Ch>> where, std::tuple<view_type, view_type> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto insert_element(optional_ptr<xml_node<Ch>> where, std::tuple<view_type, view_type> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return insert_node(where, child);
         }
-        template<typename... Args>
-        auto insert_element(optional_ptr<xml_node<Ch>> where, std::initializer_list<const Ch *> const & il, Args... args) {
-            auto child = allocate_element(il, args...);
+        auto insert_element(optional_ptr<xml_node<Ch>> where, std::initializer_list<const Ch *> const & il, view_type const & value = {}) {
+            auto child = allocate_element(il, value);
             return insert_node(where, child);
         }
 
diff --git a/test/manipulations.cpp b/test/manipulations.cpp
index ddbe00e..d1b4c4b 100644
--- a/test/manipulations.cpp
+++ b/test/manipulations.cpp
@@ -103,10 +103,11 @@ TEST(Create, NodeAttr) {
         print(doc),
         "<fish>pie</fish>\n"
     );
-    auto child = node->append_element({"urn:xmpp:fish:0", "shark"});
+    auto child = node->append_element({"urn:xmpp:fish:0", "shark"}, fn());
+    EXPECT_EQ(s.data(), child->value().data());
     EXPECT_EQ(
             print(doc),
-            "<fish>\n\t<shark xmlns=\"urn:xmpp:fish:0\"/>\n</fish>\n"
+            "<fish>\n\t<shark xmlns=\"urn:xmpp:fish:0\">tuna</shark>\n</fish>\n"
     );
     child->append_element({"urn:xmpp:fish:0", "species"}, "tiger");
     EXPECT_EQ(