[libxml++] Use nullptr instead of 0 at missing places - C++-11

[Murray Cumming <murrayc src gnome org>]

commit a96e5fa354cb59e8300a77d0b85df7332887f2c6
Author: Gaurav Gupta <g gupta samsung com>
Date:   Thu Oct 8 12:59:47 2015 +0530

    Use nullptr instead of 0 at missing places - C++-11

 libxml++/document.cc           |    6 +++---
 libxml++/nodes/element.cc      |   24 ++++++++++++------------
 libxml++/nodes/node.cc         |   12 ++++++------
 libxml++/parsers/textreader.cc |    4 ++--
 4 files changed, 23 insertions(+), 23 deletions(-)
---
diff --git a/libxml++/document.cc b/libxml++/document.cc
index fed1718..f85d70e 100644
--- a/libxml++/document.cc
+++ b/libxml++/document.cc
@@ -201,7 +201,7 @@ Dtd* Document::get_internal_subset() const
 {
   auto dtd = xmlGetIntSubset(impl_);
   if(!dtd)
-    return 0;
+    return nullptr;
 
   if(!dtd->_private)
     dtd->_private = new Dtd(dtd);
@@ -226,7 +226,7 @@ Element* Document::get_root_node()
 {
   auto root = xmlDocGetRootElement(impl_);
   if(root == nullptr)
-    return 0;
+    return nullptr;
   else
   {
     Node::create_wrapper(root);
@@ -270,7 +270,7 @@ Element* Document::create_root_node_by_import(const Node* node,
                                              bool recursive)
 {
   if (!node)
-    return 0;
+    return nullptr;
 
   //Create the node, by copying:
   auto imported_node = xmlDocCopyNode(const_cast<xmlNode*>(node->cobj()), impl_, recursive);
diff --git a/libxml++/nodes/element.cc b/libxml++/nodes/element.cc
index cb9baa9..62a6605 100644
--- a/libxml++/nodes/element.cc
+++ b/libxml++/nodes/element.cc
@@ -67,7 +67,7 @@ Attribute* Element::get_attribute(const Glib::ustring& name,
   {
     ns_uri = get_namespace_uri_for_prefix(ns_prefix);
     if (ns_uri.empty())
-      return 0; // No such prefix.
+      return nullptr; // No such prefix.
   }
 
   // The return value of xmlHasNsProp() may be either an xmlAttr*, pointing to an
@@ -82,7 +82,7 @@ Attribute* Element::get_attribute(const Glib::ustring& name,
     return reinterpret_cast<Attribute*>(attr->_private);
   }
 
-  return 0;
+  return nullptr;
 }
 
 const Attribute* Element::get_attribute(const Glib::ustring& name,
@@ -128,7 +128,7 @@ Attribute* Element::set_attribute(const Glib::ustring& name, const Glib::ustring
     return reinterpret_cast<Attribute*>(attr->_private);
   }
   else
-    return 0;
+    return nullptr;
 }
 
 void Element::remove_attribute(const Glib::ustring& name, const Glib::ustring& ns_prefix)
@@ -155,7 +155,7 @@ Element* Element::add_child_element(xmlpp::Node* previous_sibling,
   const Glib::ustring& name, const Glib::ustring& ns_prefix)
 {
   if (!previous_sibling)
-    return 0;
+    return nullptr;
 
   auto child = create_new_child_element_node(name, ns_prefix);
   auto node = xmlAddNextSibling(previous_sibling->cobj(), child);
@@ -166,7 +166,7 @@ Element* Element::add_child_element_before(xmlpp::Node* next_sibling,
   const Glib::ustring& name, const Glib::ustring& ns_prefix)
 {
   if (!next_sibling)
-    return 0;
+    return nullptr;
 
   auto child = create_new_child_element_node(name, ns_prefix);
   auto node = xmlAddPrevSibling(next_sibling->cobj(), child);
@@ -186,7 +186,7 @@ Element* Element::add_child_element_with_new_ns(xmlpp::Node* previous_sibling,
   const Glib::ustring& ns_uri, const Glib::ustring& ns_prefix)
 {
   if (!previous_sibling)
-    return 0;
+    return nullptr;
 
   auto child = create_new_child_element_node_with_new_ns(name, ns_uri, ns_prefix);
   auto node = xmlAddNextSibling(previous_sibling->cobj(), child);
@@ -198,7 +198,7 @@ Element* Element::add_child_element_before_with_new_ns(xmlpp::Node* next_sibling
   const Glib::ustring& ns_uri, const Glib::ustring& ns_prefix)
 {
   if (!next_sibling)
-    return 0;
+    return nullptr;
 
   auto child = create_new_child_element_node_with_new_ns(name, ns_uri, ns_prefix);
   auto node = xmlAddPrevSibling(next_sibling->cobj(), child);
@@ -302,13 +302,13 @@ TextNode* Element::add_child_text(const Glib::ustring& content)
     Node::create_wrapper(node);
     return static_cast<TextNode*>(node->_private);
   }
-  return 0;
+  return nullptr;
 }
 
 TextNode* Element::add_child_text(xmlpp::Node* previous_sibling, const Glib::ustring& content)
 {
   if(!previous_sibling)
-    return 0;
+    return nullptr;
 
   if(cobj()->type == XML_ELEMENT_NODE)
   {
@@ -324,13 +324,13 @@ TextNode* Element::add_child_text(xmlpp::Node* previous_sibling, const Glib::ust
     Node::create_wrapper(node);
     return static_cast<TextNode*>(node->_private);
   }
-  return 0;
+  return nullptr;
 }
 
 TextNode* Element::add_child_text_before(xmlpp::Node* next_sibling, const Glib::ustring& content)
 {
   if(!next_sibling)
-    return 0;
+    return nullptr;
 
   if(cobj()->type == XML_ELEMENT_NODE)
   {
@@ -346,7 +346,7 @@ TextNode* Element::add_child_text_before(xmlpp::Node* next_sibling, const Glib::
     Node::create_wrapper(node);
     return static_cast<TextNode*>(node->_private);
   }
-  return 0;
+  return nullptr;
 }
 
 bool Element::has_child_text() const
diff --git a/libxml++/nodes/node.cc b/libxml++/nodes/node.cc
index 16cb55f..177ca9f 100644
--- a/libxml++/nodes/node.cc
+++ b/libxml++/nodes/node.cc
@@ -238,7 +238,7 @@ const Element* Node::get_parent() const
 Element* Node::get_parent()
 {
   if(!(cobj()->parent && cobj()->parent->type == XML_ELEMENT_NODE))
-    return 0;
+    return nullptr;
 
   Node::create_wrapper(cobj()->parent);
   return static_cast<Element*>(cobj()->parent->_private);
@@ -252,7 +252,7 @@ const Node* Node::get_next_sibling() const
 Node* Node::get_next_sibling()
 {
   if(!cobj()->next)
-    return 0;
+    return nullptr;
 
   Node::create_wrapper(cobj()->next);
   return static_cast<Node*>(cobj()->next->_private);
@@ -266,7 +266,7 @@ const Node* Node::get_previous_sibling() const
 Node* Node::get_previous_sibling()
 {
   if(!cobj()->prev)
-    return 0;
+    return nullptr;
 
   Node::create_wrapper(cobj()->prev);
   return static_cast<Node*>(cobj()->prev->_private);
@@ -276,7 +276,7 @@ Node* Node::get_first_child(const Glib::ustring& name)
 {
   auto child = impl_->children;
   if(!child)
-    return 0;
+    return nullptr;
 
   do
   {
@@ -285,7 +285,7 @@ Node* Node::get_first_child(const Glib::ustring& name)
   }
   while((child = child->next));
    
-  return 0;
+  return nullptr;
 }
 
 const Node* Node::get_first_child(const Glib::ustring& name) const
@@ -320,7 +320,7 @@ void Node::remove_node(Node* node)
 Node* Node::import_node(const Node* node, bool recursive)
 {
   if (!node)
-    return 0;
+    return nullptr;
 
   //Create the node, by copying:
   auto imported_node = xmlDocCopyNode(const_cast<xmlNode*>(node->cobj()), impl_->doc, recursive);
diff --git a/libxml++/parsers/textreader.cc b/libxml++/parsers/textreader.cc
index 5eb0414..74804e3 100644
--- a/libxml++/parsers/textreader.cc
+++ b/libxml++/parsers/textreader.cc
@@ -301,7 +301,7 @@ Node* TextReader::get_current_node()
   }
     
   check_for_exceptions();
-  return 0;
+  return nullptr;
 }
 
 const Node* TextReader::get_current_node() const
@@ -329,7 +329,7 @@ Node* TextReader::expand()
   }
     
   check_for_exceptions();
-  return 0;
+  return nullptr;
 }
 
 bool TextReader::next()