https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117689
Bug ID: 117689 Summary: enum with underying type "extension" to GNU 17 is not documented Product: gcc Version: 15.0 Status: UNCONFIRMED Keywords: documentation Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- In GNU90/99/11/17 modes, GCC allows underlying types for enum to be specified. This is not documented as an extension to these modes (it is part of C23 though). Also in connection to this we could expand "Incomplete enum Types" section to talk about if you supply an underlying type for the enum tag forward declaration, you can use it as a normal type too.