libgmpxx4 from home:aurelien.doucet project
Select Your Operating System
Add repository and install manually
For SLE 12 SP5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:aurelien.doucet/SLE_12_SP5/home:aurelien.doucet.repo zypper refresh zypper install libgmpxx4