This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2024-10-26
[Moved to DR at 10/01 meeting.]
6.6 [basic.link] paragraph 4 says (among other things):A name having namespace scope has external linkage if it is the name ofThat prohibits for example:
- [...]
- a named enumeration (9.7.1 [dcl.enum]), or an unnamed enumeration defined in a typedef declaration in which the enumeration has the typedef name for linkage purposes (9.2.4 [dcl.typedef])
typedef enum { e1 } *PE; void f(PE) {} // Cannot declare a function (with linkage) using a // type with no linkage.
However, the same prohibition was not made for class scope types. Indeed, 6.6 [basic.link] paragraph 5 says:
In addition, a member function, static data member, class or enumeration of class scope has external linkage if the name of the class has external linkage.
That allows for:
struct S { typedef enum { e1 } *MPE; void mf(MPE) {} };
My guess is that this is an unintentional consequence of 6.6 [basic.link] paragraph 5, but I would like confirmation on that.
Proposed resolution:
Change text in 6.6 [basic.link] paragraph 5 from:
In addition, a member function, static data member, class or enumeration of class scope has external linkage if the name of the class has external linkage.to:
In addition, a member function, a static data member, a named class or enumeration of class scope, or an unnamed class or enumeration defined in a class-scope typedef declaration such that the class or enumeration has the typedef name for linkage purposes (9.2.4 [dcl.typedef]), has external linkage if the name of the class has external linkage.