This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 116a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-12-19
[Adopted at the February/March, 2017 meeting.]
The current wording of 7.6.1.9 [expr.static.cast] paragraph 2 appears to permit the following example:
struct B {
int i;
};
struct D : B {
int j;
B b;
};
int main() {
D d;
B &br = d.b;
D &dr = static_cast<D&>(br); // Okay?
}
Presumably such casts should only be supported if the operand object is a base class subobject, not a member subobject.
Proposed resolution (January, 2017):
Change 7.6.1.9 [expr.static.cast] paragraph 2 as follows:
...If the object of type “cv1 B” is actually a base class subobject of an object of type D, the result refers to the enclosing object of type D. Otherwise, the behavior is undefined. [Example:...