title: call C++ function in lua script and load the script then call lua function
body: <p>C++ code:</p>
  
  <pre><code>void f1() {}
  void f2() {}
  </code></pre>
  
  <p>LUA:</p>
  
  <pre><code>function t()
      f1() --defined in cpp
      f2() --defined in cpp
  </code></pre>
  
  <p>Then call t in C++:</p>
  
  <pre><code>OOLUA::Script vm;
  vm.load_file("script.lua")
  // need call t()
  </code></pre>
  
  <p>How to do this in OOLUA? I read its doc, it has complete reference, but haven't tell you how to use them in detail. And I can not find usage example by google also...</p>