libmpfrc++-dev 3.6.5+ds-2 (s390x binary) in ubuntu bionic

 MPFR C++ introduces C++ arbitrary precision numeric types; based on
 GNU MPFR --- Multiple Precision Floating-Point Reliable Library.
 .
 MPFR C++ makes possible to use MPFR calculations in the same simple
 way as calculations with numbers of built-in types double or float:
 all arithmetic and boolean operators (+, -, *, /, >, !=, etc.) are
 implemented through operator overloading technique; elementary
 mathematical functions (sqrt, pow, sin, cos, etc.) are supported.