Chris@16: // Boost.Signals library
Chris@16: 
Chris@16: // Copyright Douglas Gregor 2001-2004. Use, modification and
Chris@16: // distribution is subject to the Boost Software License, Version
Chris@16: // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: // For more information, see http://www.boost.org
Chris@16: 
Chris@16: #ifndef BOOST_SIGNALS_SLOT_CALL_ITERATOR
Chris@16: #define BOOST_SIGNALS_SLOT_CALL_ITERATOR
Chris@16: 
Chris@16: #include <memory>
Chris@16: #include <boost/iterator/iterator_facade.hpp>
Chris@16: #include <boost/smart_ptr.hpp>
Chris@16: #include <boost/signals/detail/config.hpp>
Chris@16: #include <boost/signals/connection.hpp>
Chris@16: #include <boost/optional.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16:   namespace BOOST_SIGNALS_NAMESPACE {
Chris@16:     namespace detail {
Chris@16: 
Chris@16:       // Generates a slot call iterator. Essentially, this is an iterator that:
Chris@16:       //   - skips over disconnected slots in the underlying list
Chris@16:       //   - calls the connected slots when dereferenced
Chris@16:       //   - caches the result of calling the slots
Chris@16:       template<typename Function, typename Iterator>
Chris@16:       class slot_call_iterator
Chris@16:         : public iterator_facade<slot_call_iterator<Function, Iterator>,
Chris@16:                                  typename Function::result_type,
Chris@16:                                  single_pass_traversal_tag,
Chris@16:                                  typename Function::result_type const&>
Chris@16:       {
Chris@16:         typedef iterator_facade<slot_call_iterator<Function, Iterator>,
Chris@16:                                 typename Function::result_type,
Chris@16:                                 single_pass_traversal_tag,
Chris@16:                                 typename Function::result_type const&>
Chris@16:           inherited;
Chris@16: 
Chris@16:         typedef typename Function::result_type result_type;
Chris@16: 
Chris@16:         friend class iterator_core_access;
Chris@16: 
Chris@16:       public:
Chris@16:         slot_call_iterator(Iterator iter_in, Iterator end_in, Function func,
Chris@16:                            optional<result_type> &c)
Chris@16:           : iter(iter_in), end(end_in), f(func), cache(&c)
Chris@16:         {
Chris@16:           iter = std::find_if(iter, end, is_callable());
Chris@16:         }
Chris@16: 
Chris@16:         typename inherited::reference
Chris@16:         dereference() const
Chris@16:         {
Chris@16:           if (!cache->is_initialized()) {
Chris@16:             cache->reset(f(*iter));
Chris@16:           }
Chris@16: 
Chris@16:           return cache->get();
Chris@16:         }
Chris@16: 
Chris@16:         void increment()
Chris@16:         {
Chris@16:           iter = std::find_if(++iter, end, is_callable());
Chris@16:           cache->reset();
Chris@16:         }
Chris@16: 
Chris@16:         bool equal(const slot_call_iterator& other) const
Chris@16:         {
Chris@16:           iter = std::find_if(iter, end, is_callable());
Chris@16:           other.iter = std::find_if(other.iter, other.end,
Chris@16:                                     is_callable());
Chris@16:           return iter == other.iter;
Chris@16:         }
Chris@16: 
Chris@16:       private:
Chris@16:         mutable Iterator iter;
Chris@16:         Iterator end;
Chris@16:         Function f;
Chris@16:         optional<result_type>* cache;
Chris@16:       };
Chris@16:     } // end namespace detail
Chris@16:   } // end namespace BOOST_SIGNALS_NAMESPACE
Chris@16: } // end namespace boost
Chris@16: 
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: 
Chris@16: #endif // BOOST_SIGNALS_SLOT_CALL_ITERATOR