title: Initialize wide char array
body: <p>I have a wide char variable which I want to initialize with a size of string.
  I tried following but didn't worked.</p>
  
  <pre><code>std::string s = "aaaaaaaaaaaaaaaaaaaaa"; //this could be any length 
  const int Strl = s.length();
  wchar_t wStr[Strl ]; // This throws error message as constant expression expected.
  </code></pre>
  
  <p>what option do i have to achieve this? will malloc work in this case?</p>