I have installed the GLIBCXX_3.4.21 but it always reports libstdc++.so.6(GLIBCXX_3.4.21)(64bit) is needed during the RPM install

[Jonathan Wakely]

On Wed, 10 Oct 2018 at 14:05, Ling, Darcy (NSB - CN/Qingdao)
<darcy.ling@nokia-sbell.com> wrote:
>
> Thanks very much for the response!
> Yes, the libstdc++.so.6.0.22 is not installed by rpm, when upgrade the gcc from 4.8.5 to 6.2.0, I use `make, make install` to upgrade the new version.

Then you've caused this problem by trying to mix self-installed
software and RPM-packaged software (that presumably isn't from CentOS
but some other, incompatible repository).

> Whether there is way to install gcc > 4.9 for Centos 7.5?

You can install devtoolset-7-gcc-c++ from the Software Collections,
but that won't provide a new libstdc++.so and so won't satisfy the
dependency either.

Why are you trying to install non-CentOS RPMs on CentOS?