title: convert vector<string> into char** C++
body: <p>I have a <code>vector&lt;std::string&gt;</code> variable. I need to pass it onto a method which accepts <code>char**</code>as an input parameter.</p>
  
  <p>how to do this ? If possible I need to pass a writable one. </p>
  
  <p><strong>Update 1:</strong>
  In a tool for creating a service method, i give parameters as std::vector, but it sets automatically the qualifier as &amp;, which means my method definition generated by the tool will look as:</p>
  
  <pre><code>std::string SvcImpl::myMethodname ( const std::string par1, const std::vector&lt;     std::string &gt;&amp; par2, const std::vector&lt; std::string &gt;&amp; par3 )
  {
  
  }
  </code></pre>
  
  <p>This method gets called automatically with values in the patameter passed.
  Now from inside this method I'm going to call a method in a dll in a lib folder which looks like:</p>
  
  <pre><code>int method_to_be_called(char* par1, char ** par2, char ** par3, void* pRetValue);
  </code></pre>
  
  <p>for par1 --> I'm passing (char*)par1.c_str()</p>
  
  <p>I need to know how to pass variables for par2 and par3 and for pRetValue.
  values for par2 and par3 are available in vector but the last parameter pRetValue is an output parameter that i need to return it as std::string.</p>
  
  <p>sorry if i am very confusing or asking very basic questions. </p>