Hi,

I try to use simple class tag declarations wherever possible to reduce
header-file interdependencies. I mean something like this:

// someheader.h
class Foo; // class tag declaration

class Bar {
private:
    Foo *FFoo;
};

This works fine with template as well:

template<class T> class Foo;

class Bar {
private:
    Foo<int> *FFoo;
};

Now, I wanted to do the same for the standard list class (std::list), so I
tried this:

namespace std {
    template<class T, class A = allocator<A> > class list;
}

However, if I do this, the compiler gives in an error message when it sees
the actual definition of std::list saying that the default argument has been
redeclared. So what should I do? I don't want to use this:

namespaces std {
    template<class T, class A> class list;
}

because in that case, I'd have to explicitly specify the allocator wherever
I use the list tag.

So is there any way of declaring a tag name for list? Another approach I
found useful where templatized typedefs (which don't work, of course) like
this:

template<class T> typedef std::list<T, allocator<T> list;

Any help would be appreciated.

sm


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