Reimplementations of Functions Introduced Since R-3.0.0
Description
Implementations of functions which have been introduced in R since version
3.0.0. The backports are conditionally exported which results in R
resolving the function names to the version shipped with R (if available)
and uses the implemented backports as fallback. This way package
developers can make use of the new functions without worrying about the
minimum required R version.