cmake-include_directories

• include_directories: Add include directories to the build.
  

    include_directories([AFTER|BEFORE] [SYSTEM] dir1 dir2 ...)

  将给定目录加给编译器搜索到的包含文件 .默认状况下，加到目录列表的最后. 经过设定 CMAKE_include_directories_BEFORE 为 ON 来改变. 经过使用 BEFORE or AFTER 能够加在前面或者后面. 若是设定 SYSTEM 选项 编译器认定为系统包含目录.