Title
Rule about self-or-base conversion is normatively redundant
Status
drwp
Section
11.4.8.3 [class.conv.fct]
Submitter
Brian Bi

Created on 2023-04-11.00:00:00 last changed 4 months ago

Messages

Date: 2023-04-28.19:41:23

Proposed resolution (approved by CWG 2023-04-28):

Change in 11.4.8.3 [class.conv.fct] paragraph 4 as follows:

[ Note: A conversion function is never used to convert invoked for implicit or explicit conversions of an a (possibly cv-qualified) object to the (possibly cv-qualified) same object type (or a reference to it), to a (possibly cv-qualified) base class of that type (or a reference to it), or to cv void. [ Footnote: These conversions are considered as standard conversions for the purposes of overload resolution (12.2.4.2 [over.best.ics], 12.2.4.2.5 [over.ics.ref]) and therefore initialization (9.4 [dcl.init]) and explicit casts (7.6.1.9 [expr.static.cast]). A conversion to void does not invoke any conversion function (7.6.1.9 [expr.static.cast]). Even though never directly called to perform a conversion, such conversion functions can be declared and can potentially be reached through a call to a virtual conversion function in a base class. -- end footnote ] -- end note ]

[ Example: ... ]

Date: 2023-06-15.00:00:00

[Accepted as a DR at the June, 2023 meeting.]

The rule in 11.4.8.3 [class.conv.fct] paragraph 4 is normatively redundant explanation:

A conversion function is never used to convert a (possibly cv-qualified) object to the (possibly cv-qualified) same object type (or a reference to it), to a (possibly cv-qualified) base class of that type (or a reference to it), or to cv void. [ Footnote: These conversions are considered as standard conversions for the purposes of overload resolution (12.2.4.2 [over.best.ics], 12.2.4.2.5 [over.ics.ref]) and therefore initialization (9.4 [dcl.init]) and explicit casts (7.6.1.9 [expr.static.cast]). A conversion to void does not invoke any conversion function (7.6.1.9 [expr.static.cast]). Even though never directly called to perform a conversion, such conversion functions can be declared and can potentially be reached through a call to a virtual conversion function in a base class. -- end footnote ]
History
Date User Action Args
2023-12-19 10:15:28adminsetstatus: dr -> drwp
2023-07-16 13:00:43adminsetstatus: ready -> dr
2023-04-28 19:41:23adminsetstatus: open -> ready
2023-04-11 19:11:32adminsetmessages: + msg7249
2023-04-11 00:00:00admincreate