Bug with enum computations

[Todd Veldhuizen]

This is a bug report against the 970904 snapshot.  I have Mark Mitchell's
member template patches installed, but this code doesn't use member templates.
I tried deinstalling the patches, but without success -- if this compiles
fine without the patches, it should be redirected to Mark.

1.  In the code below, gcc complains that Y<X,X>::a does not exist.  This
problem goes away if the "n = meta_max<...>::max" line in Y is replaced
with an inlined version (see comment).  Somehow the use of meta_max causes
Y<X,X>::a to disappear.

2.  If the code below is compiled with -DNO_META_MAX, an internal
compiler error occurs.


#ifndef NO_META_MAX
template<int N1, int N2>
struct meta_max {
    enum { max = (N1 > N2) ? N1 : N2 };
};
#endif

struct X {
    enum { 
       a = 0, 
       n = 0 
    };
};

template<class T1, class T2>
struct Y {

    enum { 
       a = T1::a + T2::a,

       // NB: if the next line is changed to 
       // n = (T1::n > T2::n) ? T1::n : T2::n
       // the problem goes away.

       n = meta_max<T1::n,T2::n>::max 
    };
};

int z = Y<X,X>::a;