update boost on linux

linx64/include/boost/compute/algorithm/transform_if.hpp

@@ -11,6 +11,8 @@
 #ifndef BOOST_COMPUTE_ALGORITHM_TRANSFORM_IF_HPP
 #define BOOST_COMPUTE_ALGORITHM_TRANSFORM_IF_HPP
 
+#include <boost/static_assert.hpp>
+
 #include <boost/compute/cl.hpp>
 #include <boost/compute/system.hpp>
 #include <boost/compute/command_queue.hpp>
@@ -21,11 +23,13 @@
 #include <boost/compute/detail/meta_kernel.hpp>
 #include <boost/compute/detail/iterator_range_size.hpp>
 #include <boost/compute/iterator/discard_iterator.hpp>
+#include <boost/compute/type_traits/is_device_iterator.hpp>
 
 namespace boost {
 namespace compute {
 namespace detail {
 
+// Space complexity: O(2n)
 template<class InputIterator, class OutputIterator, class UnaryFunction, class Predicate>
 inline OutputIterator transform_if_impl(InputIterator first,
                                         InputIterator last,
@@ -53,14 +57,12 @@ inline OutputIterator transform_if_impl(InputIterator first,
            << predicate(first[k1.get_global_id(0)]) << " ? 1 : 0;\n";
     k1.exec_1d(queue, 0, count);
 
-    // count number of elements to be copied
-    size_t copied_element_count =
-        ::boost::compute::count(indices.begin(), indices.end(), 1, queue);
-
     // scan indices
+    size_t copied_element_count = (indices.cend() - 1).read(queue);
     ::boost::compute::exclusive_scan(
         indices.begin(), indices.end(), indices.begin(), queue
     );
+    copied_element_count += (indices.cend() - 1).read(queue); // last scan element plus last mask element
 
     // copy values
     ::boost::compute::detail::meta_kernel k2("transform_if_do_copy");
@@ -98,6 +100,8 @@ inline discard_iterator transform_if_impl(InputIterator first,
 
 /// Copies each element in the range [\p first, \p last) for which
 /// \p predicate returns \c true to the range beginning at \p result.
+///
+/// Space complexity: O(2n)
 template<class InputIterator, class OutputIterator, class UnaryFunction, class Predicate>
 inline OutputIterator transform_if(InputIterator first,
                                    InputIterator last,
@@ -106,6 +110,8 @@ inline OutputIterator transform_if(InputIterator first,
                                    Predicate predicate,
                                    command_queue &queue = system::default_queue())
 {
+    BOOST_STATIC_ASSERT(is_device_iterator<InputIterator>::value);
+    BOOST_STATIC_ASSERT(is_device_iterator<OutputIterator>::value);
     return detail::transform_if_impl(
         first, last, result, function, predicate, false, queue
     );