[Bug c++/26110] New: using directive breaks ADL

[dg001 at t-online dot de]

When compiling the following code, an incorrect binary is produced:

--- BEGIN CODE ---
namespace test {
        double f(double f)
        {
                return f + 1.;
        }
}

double f(float d)
{
        return d;
}

int main(int argc, char *argv[]) 
{
        using test::f;

        float d = 2.;

        double result1 = f(d);

        double result2 = test::f(d);

        return 0;
}       

--- END CODE ---
The line
double result1 = f(d);
should call the function "double f(float d)", instead it calls the function
"double f(double f)" in namespace test.
This breaks argument dependent lookup. The using directive should only make
visible the function in namespace test, but not hide the global one.
If you replace "using test::f" with "using namespace test", then everything
works correctly.


gcc -v gives me:

~> gcc -v
Using built-in specs.
Target: x86_64-suse-linux
Configured with: ../configure --enable-threads=posix --prefix=/usr
--with-local-prefix=/usr/local --infodir=/usr/share/info
--mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
--enable-languages=c,c++,objc,f95,java,ada --disable-checking
--with-gxx-include-dir=/usr/include/c++/4.0.2 --enable-java-awt=gtk
--disable-libjava-multilib --with-slibdir=/lib64 --with-system-zlib
--enable-shared --enable-__cxa_atexit --without-system-libunwind
--host=x86_64-suse-linux
Thread model: posix
gcc version 4.0.2 20050901 (prerelease) (SUSE Linux)


-- 
           Summary: using directive breaks ADL
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dg001 at t-online dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26110