title: CheckCXXCompilerFlag or CheckCCompilerFlag to check a group of flags at once
body: <p>I'm starting with <code>cmake</code>, I found this module/s with this macro/s, the docs says that this macro are checking 1 flag, but I also found out that a normal set of flags works just as fine as when you use 1 flag, for example</p>
  
  <pre><code>include(CheckCXXCompilerFlag)
  CHECK_CXX_COMPILER_FLAG("-std=c++11 -O3 -v" HAS_FLAG)
  if (HAS_FLAG)
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -O3 -v")
  endif()
  </code></pre>
  
  <p>This is good for me because it makes really easy to identify where I'm setting the flags for a given platform or compiler, a 1 by 1 check would easily be too tedious and verbose to be handy.</p>
  
  <p>Is this a good way to write a <code>CMakeLists.txt</code> ? There are possible drawbacks when checking multiple flags at once ?</p>