title: What happens if an enum cannot fit into an integral type?
body: <p>I came across <a href="https://stackoverflow.com/questions/1122096/what-is-the-underlying-type-of-a-c-enum">this question</a> about the underlying types of enums, where an answers quotes Standard C++ 7.2/5 as:</p>
  
  <blockquote>
    <p>The underlying type of an enumeration is an integral type that can represent all the enumerator values defined in the enumeration. It is implementation-defined which integral type is used as the underlying type for an enumeration except that the underlying type shall not be larger than int unless the value of an enu- merator cannot fit in an int or unsigned int.</p>
  </blockquote>
  
  <p>This is pretty clear for all reasonable cases. <strong>But what happens if I make an enum so ridiculously large that it can't even fit in a long long?</strong></p>
  
  <p>(I don't know why this would ever happen in practice, but maybe I'm feeling destructive and have a free afternoon)</p>
  
  <p><strong>Is this behavior defined by the standard?</strong></p>