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The symlink to the 4.8.2 directory is nothing to worry about, it's normal for the libstdc++ headers on Red Hat Enterprise Linux (and therefore CentOS) to be arranged like that.
gcc --version will tell you the version of the gcc executable in your path.
rpm -q libstdc++-devel will tell you the version of the package that owns the C++ standard library headers.
rpm -ql libstdc++-devel will list the files installed by that package, which will include the files under /usr/include/c++/4.8.2
rpm --verify libstdc++-devel will check that you haven't messed up the C++ headers by replacing them with something else.
The error is more concerning, that implies you have messed something up. My guess would be it's in the from [...omitted by myself as it is irrelevant] part, which may actually be very relevant. std::locale should be declared in <bits/locale_classes.h> which is included before <bits/locale_facets_nonio.h>, so if it wasn't declared my guess is that you have some header that defines _LOCALE_CLASSES_H and prevents the standard library header from being read. Do not define include guards that start with underscores, they are reserved names.
I am not quite sure but below is more information
Stackoverflow: version of libc
Copy$ /lib/x86_64-linux-gnu/libc.so.6
GNU C Library (Ubuntu EGLIBC 2.19-0ubuntu6) stable release version 2.19, by Roland McGrath et al.
Copyright (C) 2014 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.
Compiled by GNU CC version 4.8.2.
Compiled on a Linux 3.13.9 system on 2014-04-12.
Available extensions:
crypt add-on version 2.1 by Michael Glad and others
GNU Libidn by Simon Josefsson
Native POSIX Threads Library by Ulrich Drepper et al
BIND-8.2.3-T5B
libc ABIs: UNIQUE IFUNC
For bug reporting instructions, please see:
<https://bugs.launchpad.net/ubuntu/+source/eglibc/+bugs>.
mandar@ubuntu:~/Desktop$