[ Post-Rapperswil ]

Wording was verified to match with the most recent WP. Jonathan Wakely and Alberto Barbati observed that the current WP has a defect that should be fixed here as well: The functions signatures fx1 and fx3 are incorrectly referring to iterator instead of const_iterator.

Moved to Tentatively Ready with revised wording after 7 positive votes on c++std-lib.