Merge pull request #722 from jmr1/vector_reserve

vector::reserve() implemented

Author: jszuppe

include/boost/compute/container/vector.hpp

@@ -435,8 +435,27 @@ class vector
 
     void reserve(size_type size, command_queue &queue)
     {
-        (void) size;
-        (void) queue;
+        if(size > max_size()){
+            throw std::length_error("vector::reserve");
+        }
+        if(capacity() < size){
+            // allocate new buffer
+            pointer new_data =
+                m_allocator.allocate(
+                    static_cast<size_type>(
+                        static_cast<float>(size) * _growth_factor()
+                    )
+                );
+
+            // copy old values to the new buffer
+            ::boost::compute::copy(m_data, m_data + m_size, new_data, queue);
+
+            // free old memory
+            m_allocator.deallocate(m_data, m_size);
+
+            // set new data
+            m_data = new_data;
+        }
     }
 
     void reserve(size_type size)

test/test_vector.cpp

@@ -62,6 +62,23 @@ BOOST_AUTO_TEST_CASE(resize)
     BOOST_CHECK_EQUAL(int_vector.size(), size_t(5));
 }
 
+BOOST_AUTO_TEST_CASE(reserve)
+{
+    const float growth_factor = 1.5f;
+
+    bc::vector<int> int_vector(10, context);
+    BOOST_CHECK_EQUAL(int_vector.size(), size_t(10));
+    BOOST_CHECK_EQUAL(int_vector.capacity(), size_t(10));
+
+    int_vector.reserve(20, queue);
+    BOOST_CHECK_EQUAL(int_vector.size(), size_t(10));
+    BOOST_CHECK_EQUAL(int_vector.capacity(), size_t(20 * growth_factor));
+
+    int_vector.reserve(5, queue);
+    BOOST_CHECK_EQUAL(int_vector.size(), size_t(10));
+    BOOST_CHECK_EQUAL(int_vector.capacity(), size_t(20 * growth_factor));
+}
+
 BOOST_AUTO_TEST_CASE(array_operator)
 {
     bc::vector<int> vector(10, context);