feat: add remaining tests in Chapter 3

tests/fig-3-6_buffers-and-accessors.cpp

@@ -0,0 +1,47 @@
+// Figure 3-6. Buffers and accessors
+// from book - Data Parallel C++
+// https://link.springer.com/book/10.1007/978-1-4842-5574-2
+
+#include <array>
+#include <sycl/sycl.hpp>
+
+constexpr int N = 42;
+
+int main() {
+  std::array<int, N> my_data{};  // filled with 0
+  {
+    sycl::queue q;
+    sycl::buffer my_buffer(my_data);
+
+    q.submit([&](sycl::handler& h) {
+      // create an accessor to update
+      // the buffer on the device
+      sycl::accessor my_accessor(my_buffer, h);
+
+      h.parallel_for(N, [=](sycl::id<1> i) { my_accessor[i]++; });
+    });
+
+    // create host accessor
+    sycl::host_accessor host_accessor(my_buffer);
+
+    std::cout << "host_accessor: ";
+    for (int i = 0; i < N; i++) {
+      // access myBuffer on host
+      std::cout << host_accessor[i] << " ";
+    }
+    std::cout << "\nmy_data_outsc: ";
+  }
+
+  // myData is updated when myBuffer is
+  // destroyed upon exiting scope
+  for (int i = 0; i < N; i++) {
+    std::cout << my_data[i] << " ";
+    if (my_data[i] != 1) {
+      std::cout << "Error at index " << i << ": expected " << 1 << ", got " << my_data[i]
+                << std::endl;
+      return 1;
+    }
+  }
+
+  std::cout << "\nTest Passed!!!" << std::endl;
+}