Add ch02 C++ threading equivalents

src/ch02/hello_cpp.cpp

@@ -0,0 +1,16 @@
+
+#include <iostream>
+#include <thread>
+
+void
+hello()
+{
+  std::cout << "Hello World\n";
+}
+
+int
+main(int argc, char* argv[])
+{
+  std::thread t(hello);
+  t.join();
+}