c++/8596: Base class template list not checked at point of declaration

c++/8596: Base class template list not checked at point of declaration

[bangerth]

>Number:         8596
>Category:       c++
>Synopsis:       Base class template list not checked at point of declaration
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          accepts-illegal
>Submitter-Id:   net
>Arrival-Date:   Fri Nov 15 17:26:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator:     Wolfgang Bangerth
>Release:        unknown-1.0
>Organization:
>Environment:
3.3 CVS and 3.2.1 pre
>Description:
In playing with PR 3907, I found that this compiles:
------------------------------
template <int s> struct U {};
template <int s> struct C : U<zs_zs_zs>{};
------------------------------
Is this supposed to work? I could not find anything in
the standard, but I'm surprised it compiles cleanly.
Of course I cannot instantiate C, since zs_zs_zs is not
known.

Further playing tells me that this has something to do
with (the non-existence of)two-stage name lookup, since
this compiles:
--------------------------
template <int s> struct U {};
template <int s> struct C : U<zs_zs_zs>{};

const int zs_zs_zs = 3;
C<1> c1;
--------------------------
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: