Title
Union member initializers
Status
cd2
Section
11.9.3 [class.base.init]
Submitter
Alisdair Meredith

Created on 2009-05-06.00:00:00 last changed 143 months ago

Messages

Date: 2009-10-15.00:00:00

[Voted into WP at October, 2009 meeting.]

Date: 2009-07-15.00:00:00

Proposed resolution (July, 2009):

  1. Change 11.5 [class.union] paragraph 1 as follows:

  2. ...If a union contains a non-static data member of reference type the program is ill-formed. At most one non-static data member of a union shall have a brace-or-equal-initializer. [Note:...
  3. Change 11.9.3 [class.base.init] paragraph 5 as follows:

  4. ...If a ctor-initializer specifies more than one mem-initializer for the same member, or for the same base class or for multiple members of the same union (including members of anonymous unions), the ctor-initializer is ill-formed.
  5. Change 11.9.3 [class.base.init] paragraph 8 as follows:

  6. ...An attempt to initialize more than one non-static data member of a union renders the program ill-formed. After the call to a constructor for class X has completed...
Date: 2009-05-06.00:00:00

11.9.3 [class.base.init] paragraph 5 forbids initializing multiple members of a union via mem-initializers:

If a ctor-initializer specifies more than one mem-initializer for the same member, for the same base class or for multiple members of the same union (including members of anonymous unions), the ctor-initializer is ill-formed.

However, there is no corresponding restriction against specifying brace-or-equal-initializers for multiple union members, nor for a non-overlapping pair of brace-or-equal-initializer and mem-initializer. This is presumably an oversight.

History
Date User Action Args
2010-03-29 00:00:00adminsetstatus: dr -> cd2
2009-11-08 00:00:00adminsetmessages: + msg2468
2009-11-08 00:00:00adminsetstatus: ready -> dr
2009-08-03 00:00:00adminsetmessages: + msg2173
2009-08-03 00:00:00adminsetstatus: open -> ready
2009-05-06 00:00:00admincreate