title: -isystem for MS Visual Studio C++ Compiler
body: <p>I usually like to have a lot of warnings enabled when programming. However, some libraries contains code that easily causes warnings (.., python, Qt, ..). When compiling with gcc I can just use -isystem instead of -I to silence that. How can I do the same with the MS compiler? I know of the warning #pragma, but I would like a solution that does not involve compiler specific code all over the place. I also know that I can turn off specific warnings, but that is not what I want either.</p>
  
  <p>BTW: isystem should be a tag of this question, but I was not allowed to do that..</p>
  
  <p>SUMMARY: I want to see <em>all</em> warnings from my code, and <em>no</em> warnings from external code.</p>