Network problem of installing docker-engine on Centos-7

After installing docker-engine on Centos-7, it failed to start by

After I use

it shows:

To see more details, I use

There were much more informations now:

The ethernet interface of docker0 can not be assigned IPv4 addresse. It seems many people meet this problem after I searching the google, but none of the solutions works for me. Consequently, I find out this solution in my environment (totally remove the network bridge):

and my docker service startup now!

The key is: docker-engine will not assign IP to docker0 interface which is already exists.

Why you should update your gcc

Consider this c++ code:

I compiled it on CentOS-5 on which the version of gcc is 4.1.2 in the first place and it report:

Can anyone find out the problem at first glance of this mess report ? The error report of c++ template is terrible difficult to understand, since I used it 9 years ago.
Then I try to compile the source on CentOS-6 with gcc-4.4.6

Looks almost the same. How about CentOS-7 with gcc-4.8.5

Aha, much better as it tell us the exact position of problem: “vec.begin()” will return a “const_iterator” which is not coherent to “iterator”.
To save your time for debugging c++ template code and enjoy life, please update your gcc.