title: Qt _USE_MATH_DEFINES
body: <p>I need to work with OpenMesh on my PC with Qt IDE, the snip of the simple *.pro file looks like:</p>
  
  <pre><code>DEFINES += _USE_MATH_DEFINES
  DEFINES += NOMINMAX
  #DEFINES += OM_STATIC_BUILD
  #OpenMesh
  INCLUDEPATH += "D:/Libraries/OpenMesh 6.3/include"
  #Debug
  LIBS += "D:/Libraries/OpenMesh 6.3/lib/OpenMeshCored.lib"
  LIBS += "D:/Libraries/OpenMesh 6.3/lib/OpenMeshToolsd.lib"
  # Release
  LIBS += "D:/Libraries/OpenMesh 6.3/lib/OpenMeshCore.lib"
  LIBS += "D:/Libraries/OpenMesh 6.3/lib/OpenMeshTools.lib"
  </code></pre>
  
  <p>However, I still got the error message: "<strong><em>C1189: #error:  "You have to define _USE_MATH_DEFINES in the compiler settings!</em></strong>"
  Can anyone help me?</p>