namespace and class within with similar name

namespace and class within with similar name

[Alexander Werth]

Hi,

I have the following code and I wonder why C++ complains.

namespace S {

class L;
class S;

}

using namespace S;

class C {
    void m(::S::L *l) {};
};

$ g++ main.5.cpp
main.5.cpp:12: error: ‘struct S::S::L’ has not been declared

Shouldn't it be clear that I wan't to access class L in
namespace S and not some L of class S in namespace S ?

Couriously I only get this error on some compilers:
gcc 4.1 and gcc 4.2.3 produce this error while
gcc 3.2.2 and xlc work as expected.

Any idea besides complaining about why I want to do this at all ? ;)

Alexander

Re: namespace and class within with similar name

[John Love-Jensen]

Hi Alexander,

> Shouldn't it be clear that I wan't to access class L in
> namespace S and not some L of class S in namespace S ?

It appears that when you injected the identifiers from namespace S into the
global namespace, the ::S::L is ambiguous between namespace S and class S
which both are (now) in the global namespace.

The compiler is going down the class S path.

I think that's a bug.

Not that I can cite chapter/verse of ISO 14882, rather I just tested against
the EDG front end, and EDG accepted the code.  (I have strong confidence
that the EDG front end is fully compliant with ISO 14882.)

> Any idea besides complaining about why I want to do this at all ? ;)

I think you should file a bug.  Maybe it will get fixed in GCC 4.4, and if
not, probably by 4.5.

http://gcc.gnu.org/bugs.html

Sincerely,
--Eljay