title: Is it possible to set cmake variables with add_subdirectory?
body: <p>I am currently using <code>add_subdirectory(${CMAKE_SOURCE_DIR}/ext/glfw)</code> to add glfw to my project.</p>
  
  <p>The problem is that once I do cmake .. &amp;&amp; make it always builds all the examples and I don't want that to happen.</p>
  
  <p>In the cmake file from glfw there is</p>
  
  <pre><code>option(GLFW_BUILD_EXAMPLES "Build the GLFW example programs" ON)
  </code></pre>
  
  <p>Is it possible to set this variable to <code>OFF</code> from my CMakeLists.txt?</p>