| Brian Silverman | 598d029 | 2018-08-04 23:56:47 -0700 | [diff] [blame^] | 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:binary_search binary_search] |
| 7 | |
| 8 | [heading Prototype] |
| 9 | |
| 10 | `` |
| 11 | template<class ForwardRange, class Value> |
| 12 | bool binary_search(const ForwardRange& rng, const Value& val); |
| 13 | |
| 14 | template<class ForwardRange, class Value, class BinaryPredicate> |
| 15 | bool binary_search(const ForwardRange& rng, const Value& val, BinaryPredicate pred); |
| 16 | `` |
| 17 | |
| 18 | [heading Description] |
| 19 | |
| 20 | `binary_search` returns `true` if and only if the value `val` exists in the range `rng`. |
| 21 | |
| 22 | [heading Definition] |
| 23 | |
| 24 | Defined in the header file `boost/range/algorithm/binary_search.hpp` |
| 25 | |
| 26 | [heading Requirements] |
| 27 | |
| 28 | [*For the non-predicate versions of binary_search:] |
| 29 | |
| 30 | * `ForwardRange` is a model of the __forward_range__ Concept. |
| 31 | * `Value` is a model of the `LessThanComparableConcept`. |
| 32 | * The ordering of objects of type `Value` is a [*/strict weak ordering/], as defined in the `LessThanComparableConcept` requirements. |
| 33 | * `ForwardRange`'s value type is the same type as `Value`. |
| 34 | |
| 35 | [*For the predicate versions of binary_search:] |
| 36 | |
| 37 | * `ForwardRange` is a model of the __forward_range__ Concept. |
| 38 | * `BinaryPredicate` is a model of the `StrictWeakOrderingConcept`. |
| 39 | * `ForwardRange`'s value type is the same type as `Value`. |
| 40 | * `ForwardRange`'s value type is convertible to `BinaryPredicate`'s argument type. |
| 41 | |
| 42 | [heading Precondition:] |
| 43 | |
| 44 | [*For the non-predicate version:] |
| 45 | |
| 46 | `rng` is ordered in ascending order according to `operator<`. |
| 47 | |
| 48 | [*For the predicate version:] |
| 49 | |
| 50 | `rng` is ordered in ascending order according to the function object `pred`. |
| 51 | |
| 52 | [heading Complexity] |
| 53 | |
| 54 | For non-random-access ranges, the complexity is `O(N)` where `N` is `distance(rng)`. |
| 55 | |
| 56 | For random-access ranges, the complexity is `O(log N)` where `N` is `distance(rng)`. |
| 57 | |
| 58 | [endsect] |
| 59 | |
| 60 | |