title: C++ output stream floating point call chain
body: <p>In C++, when I do</p>
  
  <pre><code>std::cout &lt;&lt; 1.2;
  </code></pre>
  
  <p>what is the actual chain of functions that are called to actually display the number? I realize this is compiler specific, but I am interested in particular with the Gnu libstdc++ implementation.</p>
  
  <p>In C, calling printf delegates to vfprintf, which through jump tables calls __printf_fp in glibc. I'm looking for an analogous chain in the pure C++ setting.</p>