Created on 2001-04-05.00:00:00 last changed 161 months ago
[Moved to DR at 10/01 meeting.]
Proposed resolution (04/01):
In 9.4 [dcl.init] paragraph 5, change
...set to the value 0 (zero) converted to T;
...set to the value 0 (zero), taken as an integral constant expression, converted to T; [footnote: as specified in 7.3.12 [conv.ptr], converting an integral constant expression whose value is 0 to a pointer type results in a null pointer value.]
The intent of 9.4 [dcl.init] paragraph 5 is that pointers that are zero-initialized will contain a null pointer value. Unfortunately, the wording used,
...set to the value of 0 (zero) converted to T
does not match the requirements for creating a null pointer value given in 7.3.12 [conv.ptr] paragraph 1:
A null pointer constant is an integral constant expression (7.7 [expr.const]) rvalue of integer type that evaluates to zero. A null pointer constant can be converted to a pointer type; the result is the null pointer value of that type...
The problem is that the "value of 0" in the description of zero-initialization is not specified to be an integral constant expression. Nonconstant expressions can also have the value 0, and converting a nonconst 0 to pointer type need not result in a null pointer value.
|2008-10-05 00:00:00||admin||set||status: wp -> cd1|
|2003-04-25 00:00:00||admin||set||status: dr -> wp|
|2002-05-10 00:00:00||admin||set||messages: + msg675|
|2001-11-09 00:00:00||admin||set||status: ready -> dr|
|2001-05-20 00:00:00||admin||set||messages: + msg475|