namespace boost {
  namespace call_stack {
    template<std::size_t MaxDepth> class call_stack;
    template<typename CallStack, typename AddrResolver, 
             typename OutputFormatter> 
      class call_stack_info;
    template<size_t Size> 
      void swap(call_stack< Size > & left, call_stack< Size > & right);
    template<typename CallStack, typename AddrResolver, 
             typename OutputFormatter> 
      void swap(call_stack_info< CallStack, AddrResolver, OutputFormatter > & left, 
                call_stack_info< CallStack, AddrResolver, OutputFormatter > & right);
  }
}namespace std {
  template<size_t Size> 
    void swap(boost::call_stack::call_stack< Size > & left, 
              boost::call_stack::call_stack< Size > & right);
  template<typename CallStack, typename AddrResolver, 
           typename OutputFormatter> 
    void swap(boost::call_stack::call_stack_info< CallStack, AddrResolver, OutputFormatter > & left, 
              boost::call_stack::call_stack_info< CallStack, AddrResolver, OutputFormatter > & right);
}