boost/spirit/home/support/iterators/detail/buf_id_check_policy.hpp
// Copyright (c) 2001, Daniel C. Nuffer
// Copyright (c) 2001-2011 Hartmut Kaiser
//
// 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)
#if !defined(BOOST_SPIRIT_ITERATOR_BUF_ID_CHECK_POLICY_MAR_16_2007_1108AM)
#define BOOST_SPIRIT_ITERATOR_BUF_ID_CHECK_POLICY_MAR_16_2007_1108AM
#include <boost/spirit/home/support/iterators/multi_pass_fwd.hpp>
#include <boost/spirit/home/support/iterators/detail/multi_pass.hpp>
#include <boost/core/invoke_swap.hpp>
#include <boost/config.hpp>
#include <boost/throw_exception.hpp>
#include <exception> // for std::exception
namespace boost { namespace spirit { namespace iterator_policies
{
///////////////////////////////////////////////////////////////////////////
// class illegal_backtracking
// thrown by buf_id_check CheckingPolicy if an instance of an iterator is
// used after another one has invalidated the queue
///////////////////////////////////////////////////////////////////////////
class BOOST_SYMBOL_VISIBLE illegal_backtracking : public std::exception
{
public:
illegal_backtracking() BOOST_NOEXCEPT_OR_NOTHROW {}
~illegal_backtracking() BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE {}
char const* what() const BOOST_NOEXCEPT_OR_NOTHROW BOOST_OVERRIDE
{
return "boost::spirit::multi_pass::illegal_backtracking";
}
};
///////////////////////////////////////////////////////////////////////////////
// class buf_id_check
// Implementation of the CheckingPolicy used by multi_pass
// This policy is most effective when used together with the std_deque
// StoragePolicy.
//
// If used with the fixed_size_queue StoragePolicy, it will not detect
// iterator dereferences that are out of the range of the queue.
///////////////////////////////////////////////////////////////////////////////
struct buf_id_check
{
///////////////////////////////////////////////////////////////////////
struct unique //: detail::default_checking_policy
{
unique() : buf_id(0) {}
unique(unique const& x) : buf_id(x.buf_id) {}
void swap(unique& x)
{
boost::core::invoke_swap(buf_id, x.buf_id);
}
// called to verify that everything is ok.
template <typename MultiPass>
static void docheck(MultiPass const& mp)
{
if (mp.buf_id != mp.shared()->shared_buf_id)
boost::throw_exception(illegal_backtracking());
}
// called from multi_pass::clear_queue, so we can increment the count
template <typename MultiPass>
static void clear_queue(MultiPass& mp)
{
++mp.shared()->shared_buf_id;
++mp.buf_id;
}
template <typename MultiPass>
static void destroy(MultiPass&) {}
protected:
unsigned long buf_id;
};
///////////////////////////////////////////////////////////////////////
struct shared
{
shared() : shared_buf_id(0) {}
unsigned long shared_buf_id;
};
};
}}}
#endif