message: Use nullptr in pugixml.hpp if available, see
diff: # endif
  #endif
  +// If C++ is 2011 or higher, use 'nullptr'
  +#ifndef PUGIXML_NULL
  +# if __cplusplus >= 201103
  +# define PUGIXML_NULL nullptr
  +# else
  +# define PUGIXML_NULL 0
  +# endif
  +#endif
  +
  // Character interface macros
  #ifdef PUGIXML_WCHAR_MODE
  # define PUGIXML_TEXT(t) L ## t
  @@ -661,15 +670,15 @@ namespace pugi
  #ifndef PUGIXML_NO_XPATH
  // Select single node by evaluating XPath query. Returns first node from the resulting node set.
  - xpath_node select_node(const char_t* query, xpath_variable_set* variables = 0) const;
  + xpath_node select_node(const char_t* query, xpath_variable_set* variables = PUGIXML_NULL) const;
  xpath_node select_node(const xpath_query& query) const;
  // Select node set by evaluating XPath query
  - xpath_node_set select_nodes(const char_t* query, xpath_variable_set* variables = 0) const;
  + xpath_node_set select_nodes(const char_t* query, xpath_variable_set* variables = PUGIXML_NULL) const;
  xpath_node_set select_nodes(const xpath_query& query) const;
  // (deprecated: use select_node instead) Select single node by evaluating XPath query.
  - PUGIXML_DEPRECATED xpath_node select_single_node(const char_t* query, xpath_variable_set* variables = 0) const;
  + PUGIXML_DEPRECATED xpath_node select_single_node(const char_t* query, xpath_variable_set* variables = PUGIXML_NULL) const;
  PUGIXML_DEPRECATED xpath_node select_single_node(const xpath_query& query) const;
  #endif
  @@ -1212,7 +1221,7 @@ namespace pugi
  public:
  // Construct a compiled object from XPath expression.
  // If PUGIXML_NO_EXCEPTIONS is not defined, throws xpath_exception on compilation errors.
  - explicit xpath_query(const char_t* query, xpath_variable_set* variables = 0);
  + explicit xpath_query(const char_t* query, xpath_variable_set* variables = PUGIXML_NULL);
  // Constructor
  xpath_query();
  