Incomplete types

The following are incomplete types:

• The void type
• Arrays of unknown size
• Arrays of elements that are of incomplete type
• Structure, union, or enumerations that have no definition
• Pointers to class types that are declared but not defined
• Classes that are declared but not defined

The following examples illustrate incomplete types:

      void *incomplete_ptr;
      struct dimension linear; /* no previous definition of dimension */

Related information

• The void type
• Incomplete class declarations (C++ only)