1[/ 2 Copyright 2010 Neil Groves 3 Distributed under the Boost Software License, Version 1.0. 4 (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 5/] 6[section:prev_permutation prev_permutation] 7 8[heading Prototype] 9 10`` 11template<class BidirectionalRange> 12bool prev_permutation(BidirectionalRange& rng); 13 14template<class BidirectionalRange> 15bool prev_permutation(const BidirectionalRange& rng); 16 17template<class BidirectionalRange, class Compare> 18bool prev_permutation(BidirectionalRange& rng, Compare pred); 19 20template<class BidirectionalRange, class Compare> 21bool prev_permutation(const BidirectionalRange& rng, Compare pred); 22`` 23 24[heading Description] 25 26`prev_permutation` transforms the range of elements `rng` into the lexicographically next smaller permutation of the elements if such a permutation exists. If one does not exist then the range is transformed into the lexicographically largest permutation and `false` is returned. `true` is returned when the next smaller permutation is successfully generated. 27 28The ordering relationship is determined by using `operator<` in the non-predicate versions, and by evaluating `pred` in the predicate versions. 29 30[heading Definition] 31 32Defined in the header file `boost/range/algorithm/permutation.hpp` 33 34[heading Requirements] 35 36[*For the non-predicate versions:] 37 38* `BidirectionalRange` is a model of the __bidirectional_range__ Concept. 39* `BidirectionalRange` is mutable. 40* `BidirectionalRange`'s value type is a model of the `LessThanComparableConcept`. 41* The ordering of objects of type `BidirectionalRange`'s value type is a [*/strict weak ordering/], as defined in the `LessThanComparableConcept` requirements. 42 43[*For the predicate versions:] 44 45* `BidirectionalRange` is a model of the __bidirectional_range__ Concept. 46* `BidirectionalRange` is mutable. 47* `Compare` is a model of the `StrictWeakOrderingConcept`. 48* `BidirectionalRange`'s value type is convertible to both of `Compare`'s argument types. 49 50[heading Complexity] 51 52Linear. At most `distance(rng) / 2` swaps. 53 54[endsect] 55 56 57