Added boost header

test/external/boost/signals/detail/slot_call_iterator.hpp

@@ -0,0 +1,95 @@
+// 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