attr                    Obtain an attribute of an object without
                        partial matching
file_ext                Manipulate filename extensions
in_dir                  Evaluate an expression under a specified
                        working directory
isFALSE                 Test if an object is identical to 'FALSE'
is_windows              Test for types of operating systems
native_encode           Try to use the system native encoding to
                        represent a character vector
normalize_path          Normalize paths
optipng                 Run OptiPNG on all PNG files under a directory
parse_only              Parse R code and do not keep the source
pkg_attach              Attach or load packages, and automatically
                        install missing packages if requested
read_utf8               Read / write files encoded in UTF-8
same_path               Test if two paths are the same after they are
                        normalized
strict_list             Strict lists
tojson                  A simple JSON serializer
try_silent              Try to evaluate an expression silently
