hieving link- and run-time coexistence is not a trivial
  implementation task. To achieve this goal we use inline namespaces and
  a complex organization of debug- and release-modes. The end result is
  that we have achieved per-use recompilation but have had to give up
  some checking of the <code class="code">std::basic_string</code> class template
  (namely, safe iterators).</p><div class="section"><div class="titlepage"><div><div><h5 class="title"><a id="methods.coexistence.compile"></a>Compile-time coe