title: How do I add to a wstring?
body: <p>This works with std::string</p>
  
  <pre><code>std::string class::something(char* input) {
      std::string s(input);
      s = "hai! " + s;
      return s;
  }
  </code></pre>
  
  <p>But fails if I try the same thing with wstring</p>
  
  <pre><code>std::wstring class::something(wchar_t* input) {
      std::wstring s(input);
      s = "hai! " + s;
      return s;
  }
  </code></pre>
  
  <p>How do I do the same thing with std::wstring?</p>