24 Ranges library [ranges]

24.7 Range adaptors [range.adaptors]

24.7.9 Drop while view [range.drop.while]

24.7.9.3 views​::​drop_­while [range.drop.while.adaptor]

The name views​::​drop_­while denotes a range adaptor object ([range.adaptor.object]).
For some subexpressions E and F, the expression views​::​drop_­while(E, F) is expression-equivalent to drop_­while_­view{E, F}.