Added some tests for the exported utilities.

tests/CMakeLists.txt

@@ -33,6 +33,7 @@ macro(create_test target)
         src/grouped_medians.cpp
         src/grouped_sums.cpp
         src/grouped_variances.cpp
+        src/utils.cpp
     )
 
     target_link_libraries(

tests/src/utils.cpp

@@ -0,0 +1,71 @@
+#include <gtest/gtest.h>
+
+#include "tatami_stats/utils.hpp"
+
+TEST(Utilities, Groups) {
+    {
+        std::vector<int> groups { 0, 0, 1, 1, 2, 2 };
+        EXPECT_EQ(3, tatami_stats::total_groups(groups.data(), groups.size()));
+        EXPECT_EQ(0, tatami_stats::total_groups(groups.data(), 0));
+    }
+
+    {
+        std::vector<int> groups { 5, 3, 2 };
+        EXPECT_EQ(6, tatami_stats::total_groups(groups.data(), groups.size()));
+    }
+
+    {
+        std::vector<int> groups { 0, 0, 0, 1, 1, 2 };
+        std::vector<int> expected { 3, 2, 1 };
+        auto observed = tatami_stats::tabulate_groups<int, int>(groups.data(), groups.size());
+        EXPECT_EQ(expected, observed);
+    }
+
+    {
+        std::vector<int> groups { 5 };
+        std::vector<int> expected { 0, 0, 0, 0, 0, 1 };
+        auto observed = tatami_stats::tabulate_groups<int, int>(groups.data(), groups.size());
+        EXPECT_EQ(expected, observed);
+    }
+}
+
+TEST(Utilities, OutputBuffer) {
+    {
+        std::vector<int> foo(10);
+        tatami_stats::LocalOutputBuffer<int> buffer(0, 5, 3, foo.data(), 1);
+        EXPECT_EQ(foo[4], 0); // directly uses the buffer.
+        EXPECT_EQ(foo[5], 1);
+        EXPECT_EQ(foo[6], 1);
+        EXPECT_EQ(foo[7], 1);
+        EXPECT_EQ(foo[8], 0);
+
+        buffer.data()[0] = 3;
+        EXPECT_EQ(foo[5], 3);
+        const auto& cbuffer = buffer; // check the const overload.
+        EXPECT_EQ(cbuffer.data()[0], 3);
+
+        buffer.transfer();
+        EXPECT_EQ(foo[4], 0); // directly uses the buffer.
+        EXPECT_EQ(foo[5], 3);
+        EXPECT_EQ(foo[6], 1);
+        EXPECT_EQ(foo[7], 1);
+        EXPECT_EQ(foo[8], 0);
+    }
+
+    {
+        std::vector<int> foo(10);
+        tatami_stats::LocalOutputBuffer<int> buffer(1, 5, 3, foo.data(), 2);
+
+        buffer.data()[0] = 3;
+        const auto& cbuffer = buffer; // checking the const overload.
+        EXPECT_EQ(cbuffer.data()[0], 3);
+        EXPECT_EQ(foo, std::vector<int>(10)); // buffer is not used yet...
+
+        buffer.transfer();
+        EXPECT_EQ(foo[4], 0);
+        EXPECT_EQ(foo[5], 3);
+        EXPECT_EQ(foo[6], 2);
+        EXPECT_EQ(foo[7], 2);
+        EXPECT_EQ(foo[8], 0);
+    }
+}