title: get length of `wchar_t*` in c++
body: <p>Please, how can I find out the length of a variable of type <code>wchar_t*</code> in c++?</p>
  
  <p>code example below:</p>
  
  <pre><code>wchar_t* dimObjPrefix = L"retro_";
  </code></pre>
  
  <p>I would like to find out how many characters <code>dimObjPrefix</code> contains</p>