// 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_FIRST_OWNER_POLICY_MAR_16_2007_1108AM)
|
#define BOOST_SPIRIT_ITERATOR_FIRST_OWNER_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>
|
|
namespace boost { namespace spirit { namespace iterator_policies
|
{
|
///////////////////////////////////////////////////////////////////////////
|
// class first_owner
|
// Implementation of an OwnershipPolicy used by multi_pass
|
// This ownership policy dictates that the first iterator created will
|
// determine the lifespan of the shared components. This works well for
|
// spirit, since no dynamic allocation of iterators is done, and all
|
// copies are make on the stack.
|
//
|
// There is a caveat about using this policy together with the std_deque
|
// StoragePolicy. Since first_owner always returns false from unique(),
|
// std_deque will only release the queued data if clear_queue() is called.
|
///////////////////////////////////////////////////////////////////////////
|
struct first_owner
|
{
|
///////////////////////////////////////////////////////////////////////
|
struct unique : detail::default_ownership_policy
|
{
|
unique() : first(true) {}
|
unique(unique const&) : first(false) {}
|
|
// return true to indicate deletion of resources
|
template <typename MultiPass>
|
static bool release(MultiPass& mp)
|
{
|
return mp.first;
|
}
|
|
// use swap from default policy
|
// if we're the first, we still remain the first, even if assigned
|
// to, so don't swap first. swap is only called from operator=
|
|
template <typename MultiPass>
|
static bool is_unique(MultiPass const&)
|
{
|
return false; // no way to know, so always return false
|
}
|
|
protected:
|
bool first;
|
};
|
|
////////////////////////////////////////////////////////////////////////
|
struct shared {}; // no shared data
|
};
|
|
}}}
|
|
#endif
|
