使用 Gnu Global 来索引C++代码时，会发现定义在 .h文件中的class不能被索引，下面找到一个解决方法：
TUESDAY, JUNE 14, 2011 GNU Global does not recognize C++ classes By default, GNU Global does not treat .h files as source files. If you are using a C++ project, this is most likely the behavior you want. To treat .h files as source files, set the environment variable GTAGSFORCECPP. Run the following command or put it in your shell. Note, the example below is meant for Bash users. export GTAGSFORCECPP=""