gcc/doc/gcc/extensions-to-the-c-language-family/structures-with-no-members.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 .. index:: empty structures, zero-size structures
   7
   8 .. _empty-structures:
   9
  10 Structures with No Members
  11 **************************
  12
  13 GCC permits a C structure to have no members:
  14
  15 .. code-block:: c++
  16
  17   struct empty {
  18   };
  19
  20 The structure has size zero.  In C++, empty structures are part
  21 of the language.  G++ treats empty structures as if they had a single
  22 member of type ``char``.