title: libstdc++.6.0.0.tbd or .dylib
body: <p>So folks I'm developing an app and an SDK I use require adding <code>libstdc++.6.0.0.dylib</code>, and there's no .dylib when I search it and a .tbd shows up instead.
  I just googled the difference between the two and wanna know if it's okay that I add <code>.tbd</code> into my project instead of <code>.dylib</code>?</p>