This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 119a. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2025-12-20
[Moved to DR at the November, 2014 meeting.]
According to 6.3 [basic.def.odr] paragraph 3,
A function whose name appears as a potentially-evaluated expression isodr-used if it is the unique lookup result or the selected member of a setof overloaded functions (6.5 [basic.lookup],12.2 [over.match], 12.3 [over.over]), unless it is a purevirtual function and its name is not explicitly qualified.
In the following example, consequently,S::f is odr-used butnot defined, and (because it is an undefined odr-used inline function) adiagnostic is required:
namespace { struct S { inline virtual void f() = 0; }; void (S::*p) = &S::f; }However,S::f cannot be called through such apointer-to-member, so forming a pointer-to-member should notcause a pure virtual function to be odr-used. There isimplementation divergence on this point.
Proposed resolution (April, 2013):
Change 6.3 [basic.def.odr] paragraph 3 as follows:
...A virtual member function is odr-used if it is not pure. A functionwhose name appears as a potentially-evaluated expression is odr-used if itis the unique lookup result or the selected member of a set of overloadedfunctions (6.5 [basic.lookup], 12.2 [over.match],12.3 [over.over]), unless it is a pure virtual function andeither its name is not explicitly qualifiedor theexpression forms a pointer to member (5.3.1). [Note:...