title: Using macro with string fails on VC 2015
body: <p>Why does this fail to compile?</p>
  
  <pre><code>char programDate[] = "("__DATE__")";
  </code></pre>
  
  <p>But this compiles fine (see space):</p>
  
  <pre><code>char programDate[] = "(" __DATE__")";
  </code></pre>
  
  <p>I do know VC2015 now supports literal-operators. But shouldn't that be in compilation phase? <code>__DATE__</code> should have been processed by the pre-processor. What is going on here?</p>
  
  <p>I thought of some mix-match issue with Unicode/non-Unicode build - but it doesn't help. It's not just issue with pre-defined macros, but with user defined also:</p>
  
  <pre><code>#define MACRO "abc"
  char data[] = "("MACRO")";
  </code></pre>
  
  <p>EDIT:</p>
  
  <pre><code>Error C3688 invalid literal suffix '__DATE__'; literal operator or literal operator template 'operator ""__DATE__' not found
  </code></pre>