// (C) Copyright 2008-2009 SDML (www.sdml.info)
//
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

// Copyright Andrew Sutton 2007
//
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_SETS_ORDERED_SET_INTERSECTION_HPP
#define BOOST_SETS_ORDERED_SET_INTERSECTION_HPP

namespace boost {
namespace sets {

    // Compute the intersection of a and b and store it in result.
    template <typename T, typename C, typename A>
    inline void
    intersection(const std::set<T,C,A>& s,
                 const std::set<T,C,A>& t,
                 std::set<T,C,A>& result)
    {
        std::set_intersection(s.begin(), s.end(),
                              t.begin(), t.end(),
                              std::inserter(result, result.begin()));
    }

    // Return the intersection of a and b.
    template <typename T, typename C, typename A>
    inline std::set<T,C,A>
    intersection(const std::set<T,C,A>& s, const std::set<T,C,A>& t)
    {
        std::set<T,C,A> result;
        intersection(s, t, result);
        return result;
    }

    // Remove from set a all elements that are not in both a and b. If the
    // intersection is represented by the & operator, this would be akin to
    // writing a &= b. Note that this doesn't really compute the intersection
    // in place, but simply computes the intersection and swaps the result with
    // the set a (so it just looks like it's in place).
    template <typename T, typename C, typename A>
    inline void
    intersection_inplace(std::set<T,C,A>& s, const std::set<T,C,A>& t)
    { s = intersection(s, t); }

} /* namespace sets */
} /* namespace boost */

#endif