/usr/include/boost/graph/parallel
Edit: /usr/include/boost/graph/parallel/properties.hpp (3421B)
// Copyright 2004 The Trustees of Indiana University.
// 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)
// Authors: Douglas Gregor
// Andrew Lumsdaine
#ifndef BOOST_GRAPH_PARALLEL_PROPERTIES_HPP
#define BOOST_GRAPH_PARALLEL_PROPERTIES_HPP
#ifndef BOOST_GRAPH_USE_MPI
#error "Parallel BGL files should not be included unless
has been included"
#endif
#include
#include
namespace boost {
/***************************************************************************
* Property map reduction operations
***************************************************************************/
/**
* Metafunction that produces a reduction operation for the given
* property. The default behavior merely forwards to @ref
* basic_reduce, but it is expected that this class template will be
* specified for important properties.
*/
template
struct property_reduce
{
template
class apply : public parallel::basic_reduce {};
};
/**
* Reduction of vertex colors can only darken, not lighten, the
* color. Black cannot turn black, grey can only turn black, and
* white can be changed to either color. The default color is white.
*/
template<>
struct property_reduce
{
template
class apply
{
typedef color_traits traits;
public:
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true);
template
Color operator()(const Key&) const { return traits::white(); }
template
Color operator()(const Key&, Color local, Color remote) const {
if (local == traits::white()) return remote;
else if (remote == traits::black()) return remote;
else return local;
}
};
};
/**
* Reduction of a distance always takes the shorter distance. The
* default distance value is the maximum value for the data type.
*/
template<>
struct property_reduce
{
template
class apply
{
public:
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true);
template
T operator()(const Key&) const { return (std::numeric_limits::max)(); }
template
T operator()(const Key&, T x, T y) const { return x < y? x : y; }
};
};
template<>
struct property_reduce
{
template
class apply
{
public:
BOOST_STATIC_CONSTANT(bool, non_default_resolver = true);
template
T operator()(Key key) const { return key; }
template
T operator()(Key key, T, T y) const { return y; }
};
};
template
inline void set_property_map_role(Property p, PropertyMap pm)
{
typedef typename property_traits::value_type value_type;
typedef property_reduce property_red;
typedef typename property_red::template apply reduce;
pm.set_reduce(reduce());
}
} // end namespace boost
#endif // BOOST_GRAPH_PARALLEL_PROPERTIES_HPP