help! complie error in gcc

[chenjun . bj]

I got an error when i compile the program list below under gcc, but
 it's ok under vc6.0. I found that if i place the statement #include
 <iostream> just before main or delete function _Ins, it's ok, but it
 cannot work when i put it at the start of the file.  who can help me,
 many thanks!

//=---------------------------------------------------------------------------=
 // isort.cxx

//=---------------------------------------------------------------------------=

 #include <iostream>

 /*
  * value type of an iterator
  *   by stl
  */
 template<class _Ty>
 _Ty* value_type(_Ty*)
 { return ((_Ty*)0); }

 template<class _RI, class _T>
 void _Ins(_RI _L, _T _V)
 { for (_RI _M=_L; _V<*--_M; _L=_M) *_L = *_M;
  *_L = _V;}

 template<class _RI, class _Ty>
 void _Insert_sort(_RI _IF, _RI _IL, _Ty* )
 {
   if (_IF != _IL){
     for (++_IF; _IF<_IL; ++_IF){
       _Ty V = *_IF;
       _Ins(_IF, V);
     }
   }
 }

 template<class _RI>
 void insert_sort(_RI first, _RI last)
 {
   _Insert_sort(first, last, value_type(first));
 }

 //#include <iostream>

 int main()
 {
   int a[]={9,2,5,3,0,2,3,0,3};

   insert_sort(a, a+9);

   for (int k=0; k<9; ++k) std::cout << a[k] <<"\t";

   std::cout << std::endl;

   return 0;
 }

 =====error msg=====
 $ g++ -g isort.cxx -o isort
 isort.cxx:16: error: expected `,' or `...' before numeric constant
 isort.cxx: In function `void _Ins(_RI)':
 isort.cxx:17: error: `_V' undeclared (first use this function)
 isort.cxx:17: error: (Each undeclared identifier is reported only once
 for each
 function it appears in.)
 isort.cxx:17: error: invalid type argument of `unary *'
 isort.cxx:18: error: invalid type argument of `unary *'
 isort.cxx: In function `void _Insert_sort(_RI, _RI, _Ty*) [with _RI =
 int*, _Ty
 = int]':
 isort.cxx:34:   instantiated from `void insert_sort(_RI, _RI) [with
_RI
 = int*]'

 isort.cxx:43:   instantiated from here
 isort.cxx:26: error: no matching function for call to `_Ins(int*&,
 int&)'