'Annoy' is a small C++ library for Approximate Nearest Neighbors 
 written for efficient memory usage as well an ability to load from / save to
 disk. This package provides an R interface by relying on the 'Rcpp' package,
 exposing the same interface as the original Python wrapper to 'Annoy'. See
 <https://github.com/spotify/annoy> for more on 'Annoy'. 'Annoy' is released
 under Version 2.0 of the Apache License. Also included is a small Windows
 port of 'mmap' which is released under the MIT license.

The 'APT Package Management System' provides Debian and
 Debian-derived Linux systems with a powerful system to resolve package
 dependencies. This package offers access directly from R.  This can
 only work on a system with a suitable 'libapt-pkg-dev' installation
 so functionality is curtailed if such a library is not found.

'Armadillo' is a templated C++ linear algebra library (by Conrad
 Sanderson) that aims towards a good balance between speed and ease of
 use. Integer, floating point and complex numbers are supported, as
 well as a subset of trigonometric and statistics functions. Various
 matrix decompositions are provided through optional integration with
 LAPACK and ATLAS libraries.  The 'RcppArmadillo' package includes the
 header files from the templated 'Armadillo' library. Thus users do
 not need to install 'Armadillo' itself in order to use
 'RcppArmadillo'. From release 7.800.0 on, 'Armadillo' is licensed
 under Apache License 2; previous releases were under licensed as MPL
 2.0 from version 3.800.0 onwards and LGPL-3 prior to that;
 'RcppArmadillo' (the 'Rcpp' bindings/bridge to Armadillo) is licensed
 under the GNU GPL version 2 or later, as is the rest of 'Rcpp'.

Interoperability between 'Rcpp' and the 'C++11' array and tuple
    types. Linking to this package allows fixed-length 'std::array' objects to
    be converted to and from equivalent R vectors, and 'std::tuple' objects
    converted to lists, via the as() and wrap() functions. There is also
    experimental support for 'std::span' from 'C++20'.