AI22-0068-1

!standard B.3.3(22/6)                                        23-04-21  AI22-0068-1/02

!standard B.3.3(23/6)

!class binding interpretation 23-03-23

!status Amendment 1-2022  23-03-30

!status WG9 Approved 23-06-13

!status ARG Approved 12-0-0  23-03-30

!status work item 23-03-23

!status received 23-03-23

!submitter Randall Brukardt, Project Editor

!priority Low

!difficulty Easy

!qualifier Error

!subject Fix AI22-0028-1 fix to leave lead-in alone

!summary

Simplify the change of AI22-0028-1 to simply deleting B.3.3(24/2).

!issue

AI22-0028-1 eliminates a bullet from B.3.3(24/2) and merges the first bullet into the lead-in. The authors assumed that those were the only bullets. But the actual wording is a list of 6 cases that raise Program_Error. Removing one and merging one leaves 4 bullets with no lead-in text!

Specifically, paragraphs B.3.3(22-28) now read:

Program_Error is raised upon evaluation of the predefined equality operator for an unchecked union type if either of the operands lacks inferable discriminants.

• Evaluation of an individual membership test if the subtype_mark (if any) denotes a constrained unchecked union subtype and the tested_simple_expression lacks inferable discriminants.
• Conversion from a derived unchecked union type to an unconstrained non-unchecked-union type if the operand of the conversion lacks inferable discriminants.
• Execution of the default implementation of the Write or Read attribute of an unchecked union type.
• Execution of the default implementation of the Output or Input attribute of an unchecked union type if the type lacks default discriminant values.

This layout does not work, we no longer have anything that says what happens in the case of the other bullets. We need to revert this to be much closer to the original.

!recommendation

(See Summary.)

!wording

Modify B.3.3(22/6): [This reverts it to its Ada 2012 wording]

Program_Error is raised {in the following cases:}[upon evaluation of the predefined equality operator for an unchecked union type if either of the operands lacks inferable discriminants.]

Replace B.3.3(23/5):

• Evaluation of the predefined equality operator for an unchecked union type if either of the operands lacks inferable discriminants.

!discussion

AI22-0028-1 is already WG9-Approved, so we have to have a new AI to correct this mistake.

!corrigendum B.3.3(22/6)

@drepl

Program_Error is raised upon evaluation of the predefined equality operator for an unchecked union type if either of the operands lacks inferable discriminants.

@dby

Program_Error is raised in the following cases:

!corrigendum B.3.3(23/2)

@drepl

Nothing - see conflict file.

@dby

@xbullet{Evaluation of the predefined equality operator for an unchecked union type if either of the operands lacks inferable discriminants.}

!ACATS test

This is merely a wording change, so no additional tests are needed.

!appendix