since they always need a C compiler, even when the source code is
completely in C++.
For some other packages, stated in the comment that a C compiler is
really not needed.
QDBM is an embeded database library compatible with GDBM and NDBM. It
features hash database and B+ tree database and is developed referring
to GDBM for the purpose of the following three points: higher
processing speed, smaller size of a database file, and simpler API.
This package provides the C++ interface of QDBM.