Add cpu_timer.

testing/CMakeLists.txt

@@ -2,6 +2,7 @@ set(test_srcs
   axes_metadata.cu
   benchmark.cu
   cuda_timer.cu
+  cpu_timer.cu
   float64_axis.cu
   int64_axis.cu
   params.cu

testing/cpu_timer.cu

@@ -0,0 +1,22 @@
+#include <nvbench/cpu_timer.cuh>
+
+#include "test_asserts.cuh"
+
+#include <chrono>
+#include <thread>
+
+void test_basic()
+{
+  using namespace std::literals::chrono_literals;
+
+  nvbench::cpu_timer timer;
+
+  timer.start();
+  std::this_thread::sleep_for(250ms);
+  timer.stop();
+
+  ASSERT(timer.get_duration() > 0.25);
+  ASSERT(timer.get_duration() < 0.50);
+}
+
+int main() { test_basic(); }