  // Catch and convert exceptions.
    lua_pushstring(L, s);
  } catch (std::exception& e) {
    lua_pushstring(L, e.what());
  } catch (...) {
    lua_pushliteral(L, "caught (...)");
  }
  return lua_error(L);  // Rethrow as a Lua error.
}

static int myinit(lua_State *L)
{
  ...
  // Define wrapper function and enable it.
  lua_pushlightuserdata(L, (void *)wrap_exceptions);
  luaJIT_setmode(L, -1, LUAJIT_MODE_WRAPCFUNC|LUAJIT_MODE_ON);
  lua_pop(L, 1);
  ...
}
</pre>
<p>
Note that you can only define <b>a