Use transparent functionals in placeholder expressions.

Fixes and adds regression tests for NVIDIA#1178 & NVIDIA#1229.

testing/find.cu

@@ -1,4 +1,5 @@
 #include <unittest/unittest.h>
+#include <thrust/sequence.h>
 #include <thrust/find.h>
 #include <thrust/iterator/retag.h>
 
@@ -338,3 +339,35 @@ void TestFindWithBigIndexes()
     TestFindWithBigIndexesHelper(33);
 }
 DECLARE_UNITTEST(TestFindWithBigIndexes);
+
+namespace
+{
+
+class Weird
+{
+  int value;
+
+public:
+  __host__ __device__ Weird(int val, int)
+      : value(val)
+  {}
+
+  friend __host__ __device__
+  bool operator==(int x, Weird y)
+  {
+    return x == y.value;
+  }
+};
+
+} // end anon namespace
+
+void TestFindAsymmetricEquality()
+{ // Regression test for thrust/thrust#1229
+  thrust::host_vector<int> v(1000);
+  thrust::sequence(v.begin(), v.end());
+  thrust::device_vector<int> dv(v);
+  auto result = thrust::find(dv.begin(), dv.end(), Weird(333, 0));
+  ASSERT_EQUAL(*result, 333);
+  ASSERT_EQUAL(result - dv.begin(), 333);
+}
+DECLARE_UNITTEST(TestFindAsymmetricEquality);

testing/inner_product.cu

@@ -1,8 +1,11 @@
 #include <unittest/unittest.h>
 #include <thrust/inner_product.h>
+
+#include <thrust/functional.h>
 #include <thrust/iterator/retag.h>
 #include <thrust/device_malloc.h>
 #include <thrust/device_free.h>
+#include <thrust/device_vector.h>
 
 template <class Vector>
 void TestInnerProductSimple(void)
@@ -153,3 +156,18 @@ void TestInnerProductWithBigIndexes()
     TestInnerProductWithBigIndexesHelper(33);
 }
 DECLARE_UNITTEST(TestInnerProductWithBigIndexes);
+
+void TestInnerProductPlaceholders()
+{ // Regression test for thrust/thrust#1178
+  using namespace thrust::placeholders;
+
+  thrust::device_vector<float> v1(100, 1.f);
+  thrust::device_vector<float> v2(100, 1.f);
+
+  auto result = thrust::inner_product(v1.begin(), v1.end(), v2.begin(), 0.0f,
+                                      thrust::plus<float>{},
+                                      _1 * _2 + 1.0f);
+
+  ASSERT_ALMOST_EQUAL(result, 200.f);
+}
+DECLARE_UNITTEST(TestInnerProductPlaceholders);