ext-boost/boost/range/adaptor/replaced.hpp
2014-12-07 20:45:27 +01:00

170 lines
5.4 KiB
C++

// Boost.Range library
//
// Copyright Neil Groves 2007. 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)
//
// For more information, see http://www.boost.org/libs/range/
//
#ifndef BOOST_RANGE_ADAPTOR_REPLACED_IMPL_HPP_INCLUDED
#define BOOST_RANGE_ADAPTOR_REPLACED_IMPL_HPP_INCLUDED
#include <boost/config.hpp>
#include <boost/range/adaptor/argument_fwd.hpp>
#include <boost/range/iterator_range.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/end.hpp>
#include <boost/range/value_type.hpp>
#include <boost/range/concepts.hpp>
#include <boost/iterator/iterator_adaptor.hpp>
#include <boost/iterator/transform_iterator.hpp>
#include <boost/optional/optional.hpp>
namespace boost
{
namespace range_detail
{
template< class Value >
class replace_value
{
public:
typedef const Value& result_type;
typedef const Value& first_argument_type;
// Rationale:
// The default constructor is required to allow the transform
// iterator to properly model the iterator concept.
replace_value()
{
}
replace_value(const Value& from, const Value& to)
: m_impl(data(from, to))
{
}
const Value& operator()(const Value& x) const
{
return (x == m_impl->m_from) ? m_impl->m_to : x;
}
private:
struct data
{
data(const Value& from, const Value& to)
: m_from(from)
, m_to(to)
{
}
Value m_from;
Value m_to;
};
boost::optional<data> m_impl;
};
template< class R >
class replaced_range :
public boost::iterator_range<
boost::transform_iterator<
replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type >,
BOOST_DEDUCED_TYPENAME range_iterator<R>::type > >
{
private:
typedef replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type > Fn;
typedef boost::iterator_range<
boost::transform_iterator<
replace_value< BOOST_DEDUCED_TYPENAME range_value<R>::type >,
BOOST_DEDUCED_TYPENAME range_iterator<R>::type > > base_t;
public:
typedef BOOST_DEDUCED_TYPENAME range_value<R>::type value_type;
replaced_range( R& r, value_type from, value_type to )
: base_t( make_transform_iterator( boost::begin(r), Fn(from, to) ),
make_transform_iterator( boost::end(r), Fn(from, to) ) )
{ }
};
template< class T >
class replace_holder : public holder2<T>
{
public:
replace_holder( const T& from, const T& to )
: holder2<T>(from, to)
{ }
private:
// not assignable
void operator=(const replace_holder&);
};
template< class SinglePassRange >
inline replaced_range<SinglePassRange>
operator|(
SinglePassRange& r,
const replace_holder<
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f )
{
BOOST_RANGE_CONCEPT_ASSERT((
SinglePassRangeConcept<SinglePassRange>));
return replaced_range<SinglePassRange>(r, f.val1, f.val2);
}
template< class SinglePassRange >
inline replaced_range<const SinglePassRange>
operator|(
const SinglePassRange& r,
const replace_holder<
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type>& f)
{
BOOST_RANGE_CONCEPT_ASSERT((
SinglePassRangeConcept<const SinglePassRange>));
return replaced_range<const SinglePassRange>(r, f.val1, f.val2);
}
} // 'range_detail'
using range_detail::replaced_range;
namespace adaptors
{
namespace
{
const range_detail::forwarder2<range_detail::replace_holder>
replaced =
range_detail::forwarder2<range_detail::replace_holder>();
}
template<class SinglePassRange>
inline replaced_range<SinglePassRange>
replace(SinglePassRange& rng,
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type from,
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to)
{
BOOST_RANGE_CONCEPT_ASSERT((
SinglePassRangeConcept<SinglePassRange>));
return replaced_range<SinglePassRange>(rng, from, to);
}
template<class SinglePassRange>
inline replaced_range<const SinglePassRange>
replace(const SinglePassRange& rng,
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type from,
BOOST_DEDUCED_TYPENAME range_value<SinglePassRange>::type to)
{
BOOST_RANGE_CONCEPT_ASSERT((
SinglePassRangeConcept<const SinglePassRange>));
return replaced_range<const SinglePassRange>(rng, from ,to);
}
} // 'adaptors'
} // 'boost'
#endif // include guard