title: Why don't the absolute value functions in C accept const inputs?
body: <p>In C, the prototype for the absolute value function (that accepts a float) is</p>
  
  <pre><code> float fabsf( float );
  </code></pre>
  
  <p>Why doesn't this prototype accept a constant value, like this:</p>
  
  <pre><code> float fabsf( float const );
  </code></pre>
  
  <p>fabsf won't change the value of the input, will it?</p>
  
  <p>If I have a function that accepts an input and calls fabsf, am I forced to avoid specifying the input as const?</p>
  
  <p>What is the appropriate way to handle const correctness in this situation?</p>