Dirk Eddelbuettel and Romain Francois,
with contributions by Douglas Bates and John Chambers
The Rcpp package provides a C++ library which facilitates the
integration of R and C++.

R data types (SEXP) are matched to C++ objects in a class hierarchy.  All R
types are supported (vectors, functions, environment, etc ...)  and each
type is mapped to a dedicated class. For example, numeric vectors are
represented as instances of the Rcpp::NumericVector class, environments are
represented as instances of Rcpp::Environment, functions are represented as
Rcpp::Function, etc ... The "Rcpp-introduction" vignette provides a good
entry point to Rcpp.

Conversion from C++ to R and back is driven by the templates Rcpp::wrap
and Rcpp::as which are highly flexible and extensible, as documented
in the "Rcpp-extending" vignette.

Rcpp also provides Rcpp modules, a framework that allows exposing
C++ functions and classes to the R level. The "Rcpp-modules" vignette
details the current set of features of Rcpp-modules.

Rcpp includes a concept called Rcpp sugar that brings many R functions
into C++. Sugar takes advantage of lazy evaluation and expression templates
to achieve great performance while exposing a syntax that is much nicer
to use than the equivalent low-level loop code. The "Rcpp-sugar" vignette
gives an overview of the feature.

Several examples are included, and more than 750 unit tests in over 330 unit
test functions provide additional usage examples.

An earlier version of Rcpp, containing what we now call the 'classic Rcpp
API' was written during 2005 and 2006 by Dominick Samperi.  This code has
been factored out of Rcpp into the package RcppClassic, and it is still
available for code relying on the older interface. New development, however,
should use the Rcpp package instead.

tinytest, inline, rbenchmark, pkgKitten (>= 0.1.2)

The 'Rcpp' package provides R functions as well as C++ classes which
offer a seamless integration of R and C++. Many R data types and objects can be
mapped back and forth to C++ equivalents which facilitates both writing of new
code as well as easier integration of third-party libraries. Documentation
about 'Rcpp' is provided by several vignettes included in this package, via the
'Rcpp Gallery' site at <https://gallery.rcpp.org>, the paper by Eddelbuettel and
Francois (2011, <doi:10.18637/jss.v040.i08>), the book by Eddelbuettel (2013,
<doi:10.1007/978-1-4614-6868-4>) and the paper by Eddelbuettel and Balamuta (2018,
<doi:10.1080/00031305.2017.1375990>); see 'citation("Rcpp")' for details.