pkg_search_attached() returns the packages a bare ?topic can see: every
attached package, in search path order, followed by the base packages that
are always available. This is the default search set for topic_find().
pkg_search_base() returns the base packages that are always searched.
Examples
pkg_search_attached()
#> [1] "rdtools" "stats" "graphics" "grDevices" "utils"
#> [6] "datasets" "methods" "base" "tools" "grid"
#> [11] "splines" "stats4" "tcltk" "compiler" "parallel"
pkg_search_base()
#> [1] "base" "tools" "utils" "grDevices" "graphics"
#> [6] "stats" "datasets" "methods" "grid" "splines"
#> [11] "stats4" "tcltk" "compiler" "parallel"