title: Is there a convenient way to switch the default Standard Library to Custom Library during compilation?
body: <p>I'm looking for a way to switch the default Standard Library to a Custom Library during compilation without using external scripts.</p>
  <p>I want to switch default Standard Library to Boost or Facebook Folly, Both seems has everything included in the default Standard Library. One caveat is that they use their own prefixes like <code>boost::</code> or <code>folly::</code> instead of <code>std::</code></p>
  <p>The compiler in question is clang++</p>
  <p>I need to do this to benchmark Custom Libraries for performance reasons, but I don't want to manually refactor the whole codebase into a custom Standard Library.</p>
  <p>I love to keep <code>std::</code> in code as it's so other developers don't get confused.</p>
  <p>Is this possible to do in clang?</p>