title: How to convert / evaluate an expression into a variable
body: <p>If have a string:</p>
  
  <pre><code>std::string a = "{0.0, 1.0, 2.0, 3.0}";
  </code></pre>
  
  <p>How can I convert it to so b is (double*)a ? something like:</p>
  
  <pre><code>double *b = {0.0, 1.0, 2.0, 3.0};
  </code></pre>
  
  <p>I am looking for some function that provides that literal evaluation instead of loop through the contents of the string, etc.</p>