How to scan file bytes using istreambuf_iterator<unsigned char> iit(f);

[Mike Pliam]

Phil Nicolletti posted this code to load a section of a text file given an open fstream, starting and ending points:

/// Suggested by Phil Nicolleti : http://www.codeguru.com/forum/showthread.php?t=473898
/// Modified by Mike Pliam August 19, 2014 for single byte file streams.
vector<char> GetBytes(ifstream &f, long ustart, long uend)
{
	vector<char> vb;
	const long nsz = (uend-ustart)/2;
	vb.resize(nsz); //vb = 0x00;
	if(!f.is_open()) { _RPT0(0, "No stream available in GetBytes.\n"); return vb; }

	if(ustart < 0 || uend < ustart) return vb; 


	f.clear();
	f.seekg(ustart);

	istreambuf_iterator<char> iit(f);
	//std::istreambuf_iterator<char> iit (std::cin.rdbuf()); // stdin iterator
  
	for(int ul = 0; ul < nsz; ul++) 
	{
		vb[ul] = *iit++; 
	}

	return vb;

}// GetBytes(ifstream &f, long ustart, long uend)

But now I want to load a section of bytes (unsigned char) rather than char. Unfortunately, I cannot get to cooperate:

 istreambuf_iterator<unsigned char> iit(f);

.

Error is:

error C2664: 'std::istreambuf_iterator<_Elem>::istreambuf_iterator(std::basic_streambuf<_Elem,_Traits> *) throw()' :
cannot convert parameter 1 from 'std::ifstream' to 'std::basic_streambuf<_Elem,_Traits> *'

I need bytes, not chars. Help appreciated.