add thsi command to proeference of Clion:
-D CMAKE_CXX_COMPILER=/usr/local/bin/g++-9

PS:
to find the correct version of g++, you can search it :
cd /usr/local/bin && ls
and find g++:
版权声明:本文为weixin_43085694原创文章,遵循CC 4.0 BY-SA版权协议,转载请附上原文出处链接和本声明。