Consider utilizing the dotCall64 CRAN package.
The Rcpp CRAN package allows seamless integration of C++ with
R, and is
cross-platform. The package affords many of the same benefits for the
R C interface that make C++ so appealing as a language, while
eliminating many of the pitfalls of programming to the
The package is well documented, and has an extensive repository of working examples for many tasks: the Rcpp Gallery.
Use of external libraries whose functionality is redundant with libraries already supported is strongly discouraged. In cases where the external library is complex, the author may need to supply pre-built binary versions for some platforms.
By including third-party code a package maintainer assumes responsibility for maintenance of that code. Part of the maintenance responsibility includes keeping the code up to date as bug fixes and updates are released for the mainline third-party project.