Add Lua support for std::unique_ptr and std::auto_ptr

Equivalent to Python/Ruby implementations.

Lib/lua/std_unique_ptr.i

@@ -0,0 +1,33 @@
+/* -----------------------------------------------------------------------------
+ * std_unique_ptr.i
+ *
+ * SWIG library file for handling std::unique_ptr.
+ * Memory ownership is passed from the std::unique_ptr C++ layer to the proxy
+ * class when returning a std::unique_ptr from a function.
+ * Memory ownership is passed from the proxy class to the std::unique_ptr in the
+ * C++ layer when passed as a parameter to a wrapped function.
+ * ----------------------------------------------------------------------------- */
+
+%define %unique_ptr(TYPE)
+%typemap(in, checkfn="lua_isuserdata", noblock=1) std::unique_ptr< TYPE > (void *argp = 0, int res = 0) {
+  res = SWIG_ConvertPtr(L, $input, &argp, $descriptor(TYPE *), SWIG_POINTER_RELEASE);
+  if (!SWIG_IsOK(res)) {
+    if (res == SWIG_ERROR_RELEASE_NOT_OWNED) {
+      lua_pushfstring(L, "Cannot release ownership as memory is not owned for argument $argnum of type 'TYPE *' in $symname"); SWIG_fail;
+    } else {
+      SWIG_fail_ptr("$symname", $argnum, $descriptor(TYPE *));
+    }
+  }
+  $1.reset((TYPE *)argp);
+}
+
+%typemap (out) std::unique_ptr< TYPE > %{
+  SWIG_NewPointerObj(L, $1.release(), $descriptor(TYPE *), SWIG_POINTER_OWN); SWIG_arg++;
+%}
+
+%template() std::unique_ptr< TYPE >;
+%enddef
+
+namespace std {
+  template <class T> class unique_ptr {};
+}