Install a modern GCC on Centos 7. Tested with GCC 9.

install-gcc-centos7.sh

# By default, only GCC 4.8 is installed with devtools on Centos7.
# So here we will install a recent version of GCC.
# Source: https://linuxize.com/post/how-to-install-gcc-compiler-on-centos-7/

# 1. Install the SCL.
sudo yum install centos-release-scl

# 2. See what versions are available.
sudo yum search devtoolset

# 3. Pick one and install it. The `9` will install GCC 9.
sudo yum install devtoolset-9

# 4. Enable the new compiler in your shell
scl enable devtoolset-9 bash  # if you use `fish`, replace `bash` with `fish`

# 5. Verify the version
gcc --version