boost/libs/graph/example/put-get-helper-eg.cpp
2021-10-05 21:37:46 +02:00

61 lines
1.8 KiB
C++

//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
//
// Distributed under 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)
//=======================================================================
#include <vector>
#include <string>
#include <boost/property_map/property_map.hpp>
#include <boost/concept/assert.hpp>
#ifdef BOOST_NO_STD_ITERATOR_TRAITS
#error This examples requires a compiler that provides a working std::iterator_traits
#endif
namespace foo
{
using namespace boost;
template < class RandomAccessIterator, class IndexMap >
class iterator_property_map
: public boost::put_get_helper<
typename std::iterator_traits< RandomAccessIterator >::reference,
iterator_property_map< RandomAccessIterator, IndexMap > >
{
public:
typedef std::ptrdiff_t key_type;
typedef typename std::iterator_traits< RandomAccessIterator >::value_type
value_type;
typedef typename std::iterator_traits< RandomAccessIterator >::reference
reference;
typedef boost::lvalue_property_map_tag category;
iterator_property_map(RandomAccessIterator cc = RandomAccessIterator(),
const IndexMap& _id = IndexMap())
: iter(cc), index(_id)
{
}
reference operator[](std::ptrdiff_t v) const
{
return *(iter + get(index, v));
}
protected:
RandomAccessIterator iter;
IndexMap index;
};
}
int main()
{
typedef std::vector< std::string > vec_t;
typedef foo::iterator_property_map< vec_t::iterator,
boost::identity_property_map >
pmap_t;
using namespace boost;
BOOST_CONCEPT_ASSERT((Mutable_LvaluePropertyMapConcept< pmap_t, int >));
return 0;
}