-D_GLIBCXX_USE_CXX11_ABI=1 ineffective for devtoolset-7 on CentOS 7

Question

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.

Answer 1

It is forcefully disabled in RHEL6/7.

https://bugzilla.redhat.com/show_bug.cgi?id=1546704