title: When using C headers in C++, should we use functions from std:: or the global namespace?
body: <p>C is somewhat, not exactly, a subset of C++. So we can use most of the C functions/headers in C++ by changing the name a little bit (<code>stdio.h</code> to <code>cstdio</code>, <code>stdlib.h</code> to <code>cstdlib</code>). </p>
  
  <p>My question is actually kind of semantic. In C++ code (using newest version of GCC compiler), I can call <code>printf("Hello world!");</code> and <code>std::printf("Hello world!");</code> and it works exactly the same. And in the reference I am using it also appears as <code>std::printf("Hello world!");</code>.</p>
  
  <p>My question is, is it preferred to use <code>std::printf();</code> in C++? Is there a difference?</p>