GC>namespace A {
GC>    template <typename T>
GC>    struct Key {
GC>      T value;

GC>      friend bool operator==(const Key &a, const Key &b) {
GC>         return a.value == b.value;
GC>      }

GC>    };

GC>}
GC>namespace B {
GC>    template <typename KT, typename VT>
GC>    struct MappedVal {
GC>      VT value;
GC>      A::Key<KT> key;
GC>    };

GC>    template <typename KT, typename VT>
GC>    bool operator==(const MappedVal<KT,VT> &a, const MappedVal<KT,VT> &b) {
GC>      return (a.key == b.key && a.value == b.value);
GC>    }
GC>}