title: What's the C++ suffix for long double literals?
body: <p>In C++ (and C), a floating point literal without suffix defaults to <code>double</code>, while the suffix <code>f</code> implies a <code>float</code>. But what is the suffix to get a <code>long double</code>?</p>
  
  <p>Without knowing, I would define, say,</p>
  
  <pre><code>const long double x = 3.14159265358979323846264338328;
  </code></pre>
  
  <p>But my worry is that the variable <code>x</code> contains fewer significant bits of <code>3.14159265358979323846264338328</code> than 64, because this is a <code>double</code> literal. Is this worry justified?</p>