To install the C and C++ compilers of the GNU project, you need to install a couple packages. This includes the gcc/g++ compilers themselves, cmake, and some other dependencies. Here are the commands for some common distributions:
Alpine
apk add build-base
Source: https://wiki.alpinelinux.org/wiki/GCC
Fedora (and its derivatives)
dnf groupinstall 'Development Tools'
Arch Linux (and its derivatives)
pacman -S --needed base-devel
Ubuntu/ Debian (and their derivatives)
apt install build-essential
Void Linux
xbps-install gcc
xbps-install cmake
Note: The above command also installs g++ and make
That's it!
gcc, g++, and cmake should now be installed and ready to be used for compiling programs or development.