libcarla/include/system/boost/graph/property_maps/matrix_property_map.hpp
2024-10-18 13:19:59 +08:00

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2.3 KiB
C++

// (C) Copyright 2007-2009 Andrew Sutton
//
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0 (See accompanying file
// LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GRAPH_MATRIX_PROPERTY_MAP_HPP
#define BOOST_GRAPH_MATRIX_PROPERTY_MAP_HPP
#include <boost/graph/property_maps/container_property_map.hpp>
namespace boost
{
// This property map is built specifically for property maps over
// matrices. Like the basic property map over a container, this builds
// the property abstraction over a matrix (usually a vector of vectors)
// and returns property maps over the nested containers.
template < typename Graph, typename Key, typename Matrix >
struct matrix_property_map
: boost::put_get_helper<
container_property_map< Graph, Key, typename Matrix::value_type >,
matrix_property_map< Graph, Key, Matrix > >
{
// abstract the indexing keys
typedef typename detail::choose_indexer< Graph, Key >::indexer_type
indexer_type;
// aliases for the nested container and its corresponding map
typedef typename Matrix::value_type container_type;
typedef container_property_map< Graph, Key, container_type > map_type;
typedef Key key_type;
// This property map doesn't really provide access to nested containers,
// but returns property maps over them. Since property maps are all
// copy-constructible (or should be anyways), we never return references.
// As such, this property is only readable, but not writable. Curiously,
// the inner property map is actually an lvalue pmap.
typedef map_type value_type;
typedef map_type reference;
typedef readable_property_map_tag category;
matrix_property_map() : m_matrix(0), m_graph(0) {}
matrix_property_map(Matrix& m, const Graph& g)
: m_matrix(&m), m_graph(const_cast< Graph* >(&g))
{
}
matrix_property_map(const matrix_property_map& x)
: m_matrix(x.m_matrix), m_graph(x.m_graph)
{
}
inline reference operator[](key_type k) const
{
typedef typename indexer_type::value_type Index;
Index x = indexer_type::index(k, *m_graph);
return map_type((*m_matrix)[x], *m_graph);
}
private:
mutable Matrix* m_matrix;
mutable Graph* m_graph;
};
}
#endif