// -*- C++ -*-

#ifndef LYX_ALGO_H
#define LYX_ALGO_H

#include <utility>

namespace lyx {


/// Returns true if the sequence first,last is sorted, false if not.
template <class For>
bool sorted(For first, For last)
{
	if (first == last) return true;
	For tmp = first;
	while (++tmp != last) {
		if (*tmp < *first++) return false;
	}
	return true;
}


/// Cmp is the same Cmp as you would pass to std::sort.
template <class For, class Cmp>
bool sorted(For first, For last, Cmp cmp)
{
	if (first == last) return true;
	For tmp = first;
	while (++tmp != last) {
		if (cmp(*tmp, *first++)) return false;
	}
	return true;
}


struct firster {
	template <class P1, class P2>
	P1 operator()(std::pair<P1, P2> const & p) {
		return p.first;
	}
};


template <class InputIter, class OutputIter, class Func>
OutputIter copy_if(InputIter first, InputIter last,
	       OutputIter result, Func func) 
{
	for (; first != last; ++first) {
		if (func(*first)) {
			*result++ = *first;
		}
	}
	return result;
}

}  // end of namespace lyx
#endif