To: J3                                                     J3/21-183
From: John Reid
Subject: US 21 Enum type name.
Date: 2021-October-16
Reference: 21-007r2

Discussion
----------

The meaning of "enum type" is defined by 7.6.1 Interoperable
enumerations and enum types, para 3 [88:28-89:1]:
"If enum-type-name appears in an enum-def, the enum-def defines the
enum type with that name. An enum type is an interoperable type."
and the name "enum type" is emphasized by the subclause title.

While 21-007r2 mostly uses "enum type", it occasionally uses
"interoperable enum type". This is not incorrect, but it gives the
impression that there are some enum types that are not interoperable.
The editor tells me that he choose to use that term in places to
draw the distinction between interoperable enum types and
(noninteroperable) enumeration types, but would be agreeable to any
of these choices
  a  Drop "interoperable" and just call them "enum types",
  b  Keep "interoperable", omitting it when confusion seems less
     likely (the status quo), or
  c  Keep "interoperable", and insert it nearly everywhere except
     if it makes the sentence unreadable.
He would like the committee to straw vote these alternatives.

I am strongly in favour of option a. When trying to fully understand
US 21 as it is now in 007, I soon got used to the difference between
enum and enumerator types. enum types are based on what is in the
present standard and enumerator types are the new noninteroperable
type.  I did not find the adjective "interoperable" helpful.

Edits for option a are included here.


Edits to 21-007r2
-----------------

Delete "interoperable" from "interoperable enum type" in the following
places:
[58:16] 7.3.3 Type compatibility, para 1.
[88:9,11] 7.6.1 Interoperable enumerations and enum types, para 1,
       sentences 1 and 3.
[90:NOTE 6] 7.6.1 Interoperable enumerations and enum types, NOTE 6.
[244:3] 12.6.3 Data transfer input/output list, para 6.
[276:4] 13.7.2.1 General rules, para 1.
[290:1] 13.10.3.1 List-directed input forms, para 3.
[295:2] 13.11.3.3 Namelist input values,  para 6.