libx32stdc++-9-dev - 9.3.0-22 main

This package contains the headers and static library files necessary for
building C++ programs which use libstdc++.
.
libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which
was included up to g++-2.95. The first version of libstdc++-v3 appeared
in g++-3.0.