问题
Recently, I noticed that my program has a big performance regression because the standard library implementation of gcc with version earlier than 5 makes list::size() an O(n).
I'm using CentOS 7.2 whose default gcc version is 4.8.5. So I installed scl and devtoolset-7, and rebuilt my program. However, I found that list::size() in my program is still an O(n) method, even if I explicitly make _GLIBCXX_USE_CXX11_ABI to 1.
Why? It's odd.
回答1:
It is forcefully disabled in RHEL6/7.
https://bugzilla.redhat.com/show_bug.cgi?id=1546704
来源：https://stackoverflow.com/questions/47951367/d-glibcxx-use-cxx11-abi-1-ineffective-for-devtoolset-7-on-centos-7