add_precompiled_header

function(add_precompiled_header outvar headerpath)
  get_filename_component(header"${headerpath}" NAME)
  set(pchpath ${CMAKE_CURRENT_BINARY_DIR}/${header}.dir/${CMAKE_CFG_INTDIR}/${header}.pch)
  set(flags ${CMAKE_CXX_FLAGS})
  separate_arguments(flags)
  set(flags ${flags}
    $<$:${CMAKE_CXX_FLAGS_DEBUG}>
    $<$:${CMAKE_CXX_FLAGS_RELEASE}>
    $<$:${CMAKE_CXX_FLAGS_RELWITHDEBINFO}>
    $<$:${CMAKE_CXX_FLAGS_MINSIZEREL}>
  )
  if(MSVC)
    add_custom_target(${outvar}
      COMMAND ${CMAKE_COMMAND} -E make_directory"${CMAKE_CURRENT_BINARY_DIR}/${header}.dir/${CMAKE_CFG_INTDIR}"
      COMMAND ${CMAKE_CXX_COMPILER} /c ${flags} /Fp"${pchpath}" /Yc"${header}" /Tp"${CMAKE_CURRENT_SOURCE_DIR}/${headerpath}"
      COMMENT"Precompiling header ${headerpath} ..."
      SOURCES"${headerpath}"
    )
  endif()
endfunction()