title: How can I get __LINE__ as a string constant?
body: <p>In C++ (or C) how can I get the line number (<code>__LINE__</code>) as a string?</p>
  <p>In particular, I want a macro that magically has <code>&quot;example.cpp:14&quot;</code> on line 14 of <code>example.cpp</code>. C++ automatically combines juxtaposed string literals, so I just need <code>__LINE__</code> as a string.</p>