Base.FnVarious combinators for functions.
ignore is the same as Caml.ignore. It is useful to have here so that code that rebinds ignore can still refer to Fn.ignore.
forever f runs f () until it throws an exception and returns the exception. This function is useful for read_line loops, etc.
apply_n_times ~n f x is the n-fold application of f to x.
The identity function.
See also: Sys.opaque_identity.