[Bug c++/23950] New: Two-phase name lookup crash with "using" a static const integer from a base class as template parameter

[Bug c++/23950] New: Two-phase name lookup crash with "using" a static const integer from a base class as template parameter

[lichtwerk dot x at laposte dot net]

Accessing members of base classes depending on template parameters from derived 
classes has to be done by postponing the name lookup onte the second phase of 
the standard c++ two phase name lookup (if I'm right about that). This means, 
one has to use dependent types, so you have to use scope resolution, this-> or 
a using declaration in order to access the member of the base class.

Example (this works):

template<typename T>
class Base
{
    static const int i = 0;
};
 
template<typename T>
class Derived : public Base<T>
{
    // For two phase name lookup.
    using Base<T>::i;
 
    int foo() const  { return i; }
};


In order not to obfuscate bigger classes I heavily used using declarations as 
shown in the example above (instead of writing "return Base<T>::i;"). However 
using a static const integral out of a base class using a using declaration as 
a template parameter resulted in an internal compiler error:
internal compiler error: in uses_template_parms, at cp/pt.c:4948

To reproduce the error compile this piece of code:

template<int i>
class X
{
};

template<typename T>
class Base
{
	static const int i = 0;
};

template<typename T>
class Derived : public Base<T>
{
	// For two phase name lookup.
	using Base<T>::i;

	X<i> member;
};


If I don't use a using declaration but write
    X<Base<T>::i> member;
instead of
    using Base<T>::i;
    X<i> member;
it works, though.

Thanks in advance

I'm using g++ 4.0.0 on Windows using these files
http://www.thisiscool.com/gcc_mingw.htm#gcj40

However, I have exactly the same internal compiler error using MinGW's g++ 
3.4.2.

-- 
           Summary: Two-phase name lookup crash with "using" a static const
                    integer from a base class as template parameter
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: lichtwerk dot x at laposte dot net
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23950

[Bug c++/23950] [3.4 Regression] Two-phase name lookup crash with "using" a static const integer from a base class as template parameter

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-18 16:46 -------
Confirmed, works with a very recent 4.0.2 from the cvs.

So only a 3.4 regression.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-valid-code
      Known to fail|                            |4.0.1 4.0.0 3.4.0
      Known to work|                            |4.1.0 3.3.3 4.0.2
   Last reconfirmed|0000-00-00 00:00:00         |2005-09-18 16:46:08
               date|                            |
            Summary|Two-phase name lookup crash |[3.4 Regression] Two-phase
                   |with "using" a static const |name lookup crash with
                   |integer from a base class as|"using" a static const
                   |template parameter          |integer from a base class as
                   |                            |template parameter
   Target Milestone|---                         |3.4.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23950