title: How to see source code for functions written in C/C++?
body: <p>In general, the source code for functions written in R can be looked up just by typing the name of the function on R console. How do you do it for functions which are written in C or C++?</p>
  
  <p>For e.g. when I try and look up the code for <code>lapply()</code> function, it shows me this - </p>
  
  <pre><code>function (X, FUN, ...) 
  {
      FUN &lt;- match.fun(FUN)
      if (!is.vector(X) || is.object(X)) 
          X &lt;- as.list(X)
      .Internal(lapply(X, FUN))
  }
  &lt;bytecode: 0x0000000007384128&gt;
  &lt;environment: namespace:base&gt;
  </code></pre>
  
  <p>which doesn't help in anyways to understand what exactly this function is doing.</p>