This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 113d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-03-20


510. Default initialization of POD classes?

Section: 11.9  [class.init]     Status: CD1     Submitter: Mike Miller     Date: 18 Mar 2005

[Voted into WP at April, 2006 meeting.]

9.4 [dcl.init] paragraph 10 makes it clear that non-static POD class objects with no initializer are left uninitialized and have an indeterminate initial value:

If no initializer is specified for an object, and the object is of (possibly cv-qualified) non-POD class type (or array thereof), the object shall be default-initialized; if the object is of const-qualified type, the underlying class type shall have a user-declared default constructor. Otherwise, if no initializer is specified for a non-static object, the object and its subobjects, if any, have an indeterminate initial value; if the object or any of its subobjects are of const-qualified type, the program is ill-formed.

11.9 [class.init] paragraph 1, however, implies that all class objects without initializers, whether POD or not, are default-initialized:

When no initializer is specified for an object of (possibly cv-qualified) class type (or array thereof), or the initializer has the form (), the object is initialized as specified in 9.4 [dcl.init]. The object is default-initialized if there is no initializer, or value-initialized if the initializer is ().

Proposed resolution (October, 2005):

Remove the indicated words from 11.9 [class.init] paragraph 1:

When no initializer is specified for an object of (possibly cv-qualified) class type (or array thereof), or the initializer has the form (), the object is initialized as specified in 9.4 [dcl.init]. The object is default-initialized if there is no initializer, or value-initialized if the initializer is ().