Identifier expressions (C++ only)

An identifier expression, or id-expression, is a restricted form of primary expression. Syntactically, an id-expression requires a higher level of complexity than a simple identifier to provide a name for all of the language elements of C++.

An id-expression can be either a qualified or unqualified identifier. It can also appear after the dot and arrow operators.

Identifier expression syntax
 
>>-+-| unqualified_id |-+--------------------------------------><
   '-| qualified_id |---'
 
unqualified_id:
 
|--+-identifier-------------+-----------------------------------|
   +-operator_function_id---+
   +-conversion_function_id-+
   +-~--class_name----------+
   '-template_id------------'
 
qualified_id:
 
|--+-::--+-identifier-----------+-------------------------------------------------------------------------------+--|
   |     +-operator_function_id-+                                                                               |
   |     '-template_id----------'                                                                               |
   |         .------------------------------------------.                                                       |
   |         V                                          |                                                       |
   '-+----+----+--------------------------------------+-+--class_or_namespace--::--+----------+--unqualified_id-'
     '-::-'    '-class_or_namespace--::--+----------+-'                            '-template-'
                                         '-template-'
 

Related information

• Identifiers
• Declarators