unique: test with ForwardIterator parameters

Author: upsj

testing/unique.cu

@@ -1,4 +1,5 @@
 #include <unittest/unittest.h>
+#include <unittest/iterator_helpers.h>
 #include <thrust/unique.h>
 #include <thrust/functional.h>
 #include <thrust/iterator/discard_iterator.h>
@@ -163,11 +164,13 @@ void TestUniqueSimple(void)
     data[8] = 31; 
     data[9] = 37; 
 
-    typename Vector::iterator new_last;
+    forward_iterator_wrapper<typename Vector::iterator> new_last;
+    const auto begin = make_forward_iterator_wrapper(data.begin());
+    const auto end = make_forward_iterator_wrapper(data.end());
 
-    new_last = thrust::unique(data.begin(), data.end());
+    new_last = thrust::unique(begin, end);
 
-    ASSERT_EQUAL(new_last - data.begin(), 7);
+    ASSERT_EQUAL(thrust::distance(begin, new_last), 7);
     ASSERT_EQUAL(data[0], 11);
     ASSERT_EQUAL(data[1], 12);
     ASSERT_EQUAL(data[2], 20);
@@ -176,9 +179,9 @@ void TestUniqueSimple(void)
     ASSERT_EQUAL(data[5], 31);
     ASSERT_EQUAL(data[6], 37);
 
-    new_last = thrust::unique(data.begin(), new_last, is_equal_div_10_unique<T>());
+    new_last = thrust::unique(begin, new_last, is_equal_div_10_unique<T>());
 
-    ASSERT_EQUAL(new_last - data.begin(), 3);
+    ASSERT_EQUAL(thrust::distance(begin, new_last), 3);
     ASSERT_EQUAL(data[0], 11);
     ASSERT_EQUAL(data[1], 20);
     ASSERT_EQUAL(data[2], 31);
@@ -327,11 +330,16 @@ void TestUniqueCountSimple(void)
     data[8] = 31;
     data[9] = 37;
 
-    int count = thrust::unique_count(data.begin(), data.end());
+    int count = thrust::unique_count(
+        make_forward_iterator_wrapper(data.begin()),
+        make_forward_iterator_wrapper(data.end()));
 
     ASSERT_EQUAL(count, 7);
 
-    int div_10_count = thrust::unique_count(data.begin(), data.end(), is_equal_div_10_unique<T>());
+    int div_10_count = thrust::unique_count(
+        make_forward_iterator_wrapper(data.begin()),
+        make_forward_iterator_wrapper(data.end()),
+        is_equal_div_10_unique<T>());
 
     ASSERT_EQUAL(div_10_count, 3);
 }

testing/unittest/iterator_helpers.h

@@ -0,0 +1,52 @@
+#pragma once
+
+#include <iterator>
+
+
+// Wraps an existing iterator into a forward iterator,
+// thus removing some of its functionality
+template <typename Iterator>
+struct forward_iterator_wrapper {
+    // LegacyIterator requirements
+    using reference = typename Iterator::reference;
+    using pointer = typename Iterator::pointer;
+    using value_type = typename Iterator::value_type;
+    using difference_type = typename Iterator::difference_type;
+    using iterator_category = std::forward_iterator_tag;
+
+    __host__ __device__ reference operator*() const {
+        return *wrapped;
+    }
+
+    __host__ __device__ forward_iterator_wrapper& operator++() {
+        ++wrapped;
+        return *this;
+    }
+
+    // LegacyInputIterator
+    __host__ __device__ bool operator==(const forward_iterator_wrapper& other) {
+        return wrapped == other.wrapped;
+    }
+
+    __host__ __device__ bool operator!=(const forward_iterator_wrapper& other) {
+        return !(*this == other);
+    }
+
+    __host__ __device__ forward_iterator_wrapper operator++(int) {
+        auto cpy = *this;
+        ++(*this);
+        return cpy;
+    }
+    
+    __host__ __device__ pointer operator->() const {
+        return wrapped.operator->();
+    }
+
+    Iterator wrapped;
+};
+
+
+template <typename Iterator>
+forward_iterator_wrapper<Iterator> make_forward_iterator_wrapper(Iterator it) {
+    return {it};
+}