/*
 * Copyright (c) 2005
 * Evan Teran
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notice appears in all copies and that both the
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the same name not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission. We make no representations about the
 * suitability this software for any purpose. It is provided "as is"
 * without express or implied warranty.
 */

#ifndef BIT_OPS_20051205_H_
#define BIT_OPS_20051205_H_

#include <climits>	// for CHAR_BIT

namespace bit_ops {

	/*
	 *  the reason why we need the "mask" constant is 
	 *  because some platforms make >> on negative values
	 *  arithmetic (which shifts in the sign bit, not 0)
	 *  using the mask allows this to work with both signed 
	 *  and unsigned types
	 */
	template <class T>
	inline T rol(T v, int n) {
		static const unsigned int bits(CHAR_BIT * sizeof(T));
		const T mask(~(T(-1) << n));
		return (v << n) | ((v >> (bits - n)) & mask);
	}

	template <class T>
	inline T ror(T v, int n) { return rol(v, -n); }
}
#endif