For openSUSE Leap 15.6 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/openSUSE_Leap_15.6/devel:gcc.repo
zypper refresh
zypper install cpp33
For openSUSE Leap 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/openSUSE_Leap_15.5/devel:gcc.repo
zypper refresh
zypper install cpp33
For SLE-15 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/SLE-15/devel:gcc.repo
zypper refresh
zypper install cpp33
For SLE-12 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/SLE-12/devel:gcc.repo
zypper refresh
zypper install cpp33
For SLE-11 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/SLE-11/devel:gcc.repo
zypper refresh
zypper install cpp33
For SLE-10 SDK run the following as root:
zypper addrepo https://download.opensuse.org/repositories/devel:gcc/SLE-10_SDK/devel:gcc.repo
zypper refresh
zypper install cpp33