William S Fulton wrote:test.cxx:15: warning: non-local variable ‘<unnamed>::<anonymous enum> <unnamed>::Instance’ uses anonymous type
Just grepping the sources for the warning, I find this comment /* [basic.link]: A name with no linkage (notably, the name of a class or enumeration declared in a local scope) shall not be used to declare an entity with linkage. Only check this for public decls for now. */ Also this: /* DRs 132, 319 and 389 seem to indicate types with no linkage can only be used to declare extern "C" entities. Since it's not always an error in the ISO C++ 90 Standard, we only issue a warning. */
static enum { foo, bar = 10 } Instance;
The "public decls" comment above means that we deliberately don't emit the warning for static variables, but it is possible this may change in the future. It may depend on how the defect reports get resolved.
I'm not a C++ expert, and don't have a copy of the C++ standard, so I can't comment further.
Interesting, thanks James. Indeed, the warning disappears when the enum declaration is made extern "C" and that is good enough for me :)
William
