token_iterator_base copy constructor

From: Gennadiy E. Rozental (rogeeff_at_[hidden])
Date: 2001-10-17 17:42:50

Hi,

I think it would be more portable if we rewrite token_iterator_base 
copy constructor following way:

template<class T>
token_iterator_base(const token_iterator_base<T>& other)
:p_(other.p_.first,other.p_.second),valid_(other.valid_){}
 __________________________________

now implementation do not rely on presence of templeted copy 
constructors in std::pair.

Gennadiy.