title: C++ std::printf("%u", 5) adds a number after the expected output
body: <p>The output of the following code is <code>51</code> instead of the expected <code>5</code>. I use Xcode 6.4 with the LLVM compiler on Mac OS Yosemite 10.10.4.</p>
  
  <pre class="lang-cpp prettyprint-override"><code>#include &lt;iostream&gt;
  
  int main(int argc, const char * argv[]) {
    std::cout &lt;&lt; std::printf("%u", 5) &lt;&lt; std::endl;
  
    return 0;
  }
  </code></pre>
  
  <p>If have tried to supply an <code>int</code>, <code>unsigned long</code> and <code>uint32_t</code>, and I have swapped the <code>%u</code> for a <code>%d</code> and <code>%lu</code>, but I always get the same result: A strange number being after the intended <code>printf</code> output. Swapping the <code>5</code> for another number results in another unexpected number being added to the output. This is in a fresh project with no other code added. What am I overlooking?</p>