Seamless R and C++ Integration
Description
The Rcpp package provides R functions as well as a C++
library which facilitate 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.
Rcpp attributes provide a high-level syntax for declaring C++ functions
as callable from R and automatically generating the code
required to invoke them. Attributes are intended to facilitate
both interactive use of C++ within R sessions as well as to
support R package development. Attributes are built on top of
Rcpp modules and their implementation is based on previous work
in the inline package.
Many examples are included, and over 870 unit tests in over 390 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 should always use this Rcpp
package instead.