title: hiding namespaces in C++
body: <p>I've read some answers to other similar questions on SO that seemed to indicate that it was possible to hide a namespace away (for the purpose of hiding implementation details), but they didn't say how.</p>
  
  <p>So for example, if I wanted a <code>namespace A</code> which contained a <code>namespace B</code>, and <code>B</code> had some nasty implementation details for features in <code>A</code> that I wanted hidden from the end user, is there some sort of linker trickery that I can use so that <code>B</code> is not visible outside of <code>A</code>, but <code>A</code> is still visible to the rest of the program?</p>