Install g++/gcc 4.8.2 in CentOS 6.6 ref: http://qiita.com/giwa/items/28c754d8fc2936c0f6d2

file0.txt

$ wget http://people.centos.org/tru/devtools-2/devtools-2.repo -O /etc/yum.repos.d/devtools-2.repo
$ yum install devtoolset-2-gcc devtoolset-2-binutils
$ yum install devtoolset-2-gcc-c++ devtoolset-2-gcc-gfortran

file1.txt

$ /opt/rh/devtoolset-2/root/usr/bin/gcc --version
gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-15)
Copyright (C) 2013 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

file2.txt

scl enable devtoolset-2 bash

file3.txt

source /opt/rh/devtoolset-2/enable