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

1113. Linkage of namespace member of unnamed namespace

[Voted into the WP at the November, 2010 meeting.]

It is odd that, in the following example, N has no linkage but g has external linkage:

    namespace {
      namespace N // has no linkage
      {
        void g(); // has external linkage
      }
    }

Proposed resolution (August, 2010):

Change 6.6 [basic.link] paragraph 4 as follows:

An unnamed namespace or a namespace declared directly or indirectly within an unnamed namespace has internal linkage. All other namespaces have external linkage. A name having namespace scope that has not been given internal linkage above has external linkage the same linkage as the enclosing namespace if it is the name of

• a variable, unless it has internal linkage; or

• a function, unless it has internal linkage; or

• a named class (Clause 11 [class]), or an unnamed class defined in a typedef declaration in which the class has the typedef name for linkage purposes (9.2.4 [dcl.typedef]); or

• 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]); or

• an enumerator belonging to an enumeration with external linkage; or

• a template, unless it is a function template that has internal linkage (Clause 13 [temp]); or.

• a namespace (9.8 [basic.namespace]), unless it is declared within an unnamed namespace.