26 Ranges library [ranges]

26.7 Range adaptors [range.adaptors]

26.7.6 All view [range.all] General [range.all.general]

views​::​all returns a view that includes all elements of its range argument.
The name views​::​all denotes a range adaptor object ([range.adaptor.object]).
Given a subexpression E, the expression views​::​all(E) is expression-equivalent to:
  • decay-copy(E) if the decayed type of E models view.
  • Otherwise, ref_view{E} if that expression is well-formed.
  • Otherwise, owning_view{E}.