title: Checking if a string contains a substring, regardless of capitalization
body: <p>Suppose I have some string, str.</p>
  
  <p>I was to check if str contains a keyword: "samples"
  However, "samples" could be in any form of capitalization such as: "Samples" "SamPleS", "SAMPLES".</p>
  
  <p>this is what I am trying:</p>
  
  <pre><code>string str = "this is a FoO test";
  if (str.find("foo") != std::string::npos){
      std::cout &lt;&lt; "WORKS";
  }
  </code></pre>
  
  <p>This does not detect the "FoO" substring. Is there some sort of argument I can pass through to ignore capitalization? Or should I be using something else entirely?</p>