Iterator in a template

I've used map iterators before; this is my first time making a template.
hvec (hexagonal vector) is an integral (in the mathematical sense) type
representing a point in a hexagonal lattice. A harray is an array
subscripted by an hvec. Currently I use only bytes as the elements, but I
will need to store larger things in harrays, so I made it a template. I
wrote this code to clear all elements in the harray:

template <typename T> class harray
{map<hvec,T *> index;
 public:
 T& operator[](hvec i);
 void clear();
 };

template <typename T> T& harray<T>::operator[](hvec i)
{hvec q,r;
 q=i/PAGEMOD;
 r=i%PAGEMOD;
 if (!index[q])
    index[q]=(T*)calloc(PAGESIZE,sizeof(T));
 return index[q][r.pageinx()];
 }

template <typename T> void harray<T>::clear()
{map<hvec,T *>::iterator i; // line 78
 for (i=index.start();i!=index.end();i++)
     {free(i->second);
      i->second=NULL;
      }
 }

When I try to compile it, I get this error:

In file included from /home/phma/hexcode/hexcode.cpp:5:
/home/phma/hexcode/hvec.h: In member function 'void harray<T>::clear()':
/home/phma/hexcode/hvec.h:78: error: expected ';' before 'i'
/home/phma/hexcode/hvec.h:79: error: 'i' was not declared in this scope

How can I fix it?