gcc/testsuite/gcc.dg/gnu23-enum-1.c

   1 /* Test C23 enumerations with fixed underlying type together with GNU
   2    extensions: an enum cannot be forward declared without a fixed underlying
   3    type and then declared or defined with one.  */
   4 /* { dg-do compile } */
   5 /* { dg-options "-std=gnu23" } */
   6
   7 enum e1;
   8 enum e1 : int; /* { dg-error "'enum' declared both with and without fixed underlying type" } */
   9
  10 enum e2;
  11 enum e2 : long { A }; /* { dg-error "'enum' declared both with and without fixed underlying type" } */