// Boost.Signals library | |
// Copyright Douglas Gregor 2001-2004. 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 | |
#ifndef BOOST_SIGNALS_SLOT_CALL_ITERATOR | |
#define BOOST_SIGNALS_SLOT_CALL_ITERATOR | |
#include <memory> | |
#include <boost/iterator/iterator_facade.hpp> | |
#include <boost/smart_ptr.hpp> | |
#include <boost/signals/detail/config.hpp> | |
#include <boost/signals/connection.hpp> | |
#include <boost/optional.hpp> | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_PREFIX | |
#endif | |
namespace boost { | |
namespace BOOST_SIGNALS_NAMESPACE { | |
namespace detail { | |
// Generates a slot call iterator. Essentially, this is an iterator that: | |
// - skips over disconnected slots in the underlying list | |
// - calls the connected slots when dereferenced | |
// - caches the result of calling the slots | |
template<typename Function, typename Iterator> | |
class slot_call_iterator | |
: public iterator_facade<slot_call_iterator<Function, Iterator>, | |
typename Function::result_type, | |
single_pass_traversal_tag, | |
typename Function::result_type const&> | |
{ | |
typedef iterator_facade<slot_call_iterator<Function, Iterator>, | |
typename Function::result_type, | |
single_pass_traversal_tag, | |
typename Function::result_type const&> | |
inherited; | |
typedef typename Function::result_type result_type; | |
friend class iterator_core_access; | |
public: | |
slot_call_iterator(Iterator iter_in, Iterator end_in, Function func, | |
optional<result_type> &c) | |
: iter(iter_in), end(end_in), f(func), cache(&c) | |
{ | |
iter = std::find_if(iter, end, is_callable()); | |
} | |
typename inherited::reference | |
dereference() const | |
{ | |
if (!cache->is_initialized()) { | |
cache->reset(f(*iter)); | |
} | |
return cache->get(); | |
} | |
void increment() | |
{ | |
iter = std::find_if(++iter, end, is_callable()); | |
cache->reset(); | |
} | |
bool equal(const slot_call_iterator& other) const | |
{ | |
iter = std::find_if(iter, end, is_callable()); | |
other.iter = std::find_if(other.iter, other.end, | |
is_callable()); | |
return iter == other.iter; | |
} | |
private: | |
mutable Iterator iter; | |
Iterator end; | |
Function f; | |
optional<result_type>* cache; | |
}; | |
} // end namespace detail | |
} // end namespace BOOST_SIGNALS_NAMESPACE | |
} // end namespace boost | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_SUFFIX | |
#endif | |
#endif // BOOST_SIGNALS_SLOT_CALL_ITERATOR |