title: What is a good example of leveraging the differences between int*_t, int_fast*_t and int_least*_t in C++11?
body: <p>According to online documentation, there are differences in between these fixed width integer types. For <code>int*_t</code> we fixed the width to whatever the value of <code>*</code> is. Yet for the other two types, the adjectives <em>fastest</em> and <em>smallest</em> are used in the description to request the fastest or the smallest instances provided by the underlying data model.</p>
  
  <p>What are the objective meanings of "the fastest" or the "smallest"? What is an example in where this would be advantageous or even necessary?</p>