| 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:equal_range equal_range] |
| 7 | |
| 8 | [heading Prototype] |
| 9 | |
| 10 | `` |
| 11 | template< |
| 12 | class ForwardRange, |
| 13 | class Value |
| 14 | > |
| 15 | std::pair<typename range_iterator<ForwardRange>::type, |
| 16 | typename range_iterator<ForwardRange>::type> |
| 17 | equal_range(ForwardRange& rng, const Value& val); |
| 18 | |
| 19 | template< |
| 20 | class ForwardRange, |
| 21 | class Value |
| 22 | > |
| 23 | std::pair<typename range_iterator<const ForwardRange>::type, |
| 24 | typename range_iterator<const ForwardRange>::type> |
| 25 | equal_range(const ForwardRange& rng, const Value& val); |
| 26 | |
| 27 | template< |
| 28 | class ForwardRange, |
| 29 | class Value, |
| 30 | class SortPredicate |
| 31 | > |
| 32 | std::pair<typename range_iterator<ForwardRange>::type, |
| 33 | typename range_iterator<ForwardRange>::type> |
| 34 | equal_range(ForwardRange& rng, const Value& val, SortPredicate pred); |
| 35 | |
| 36 | template< |
| 37 | class ForwardRange, |
| 38 | class Value, |
| 39 | class SortPredicate |
| 40 | > |
| 41 | std::pair<typename range_iterator<const ForwardRange>::type, |
| 42 | typename range_iterator<const ForwardRange>::type> |
| 43 | equal_range(const ForwardRange& rng, const Value& val, SortPredicate pred); |
| 44 | `` |
| 45 | |
| 46 | [heading Description] |
| 47 | |
| 48 | `equal_range` returns a range in the form of a pair of iterators where all of the elements are equal to `val`. If no values are found that are equal to `val`, then an empty range is returned, hence `result.first == result.second`. For the non-predicate versions of `equal_range` the equality of elements is determined by `operator<`. |
| 49 | For the predicate versions of `equal_range` the equality of elements is determined by `pred`. |
| 50 | |
| 51 | [heading Definition] |
| 52 | |
| 53 | Defined in the header file `boost/range/algorithm/equal_range.hpp` |
| 54 | |
| 55 | [heading Requirements] |
| 56 | |
| 57 | [*For the non-predicate versions:] |
| 58 | |
| 59 | * `ForwardRange` is a model of the __forward_range__ Concept. |
| 60 | * `Value` is a model of the `LessThanComparableConcept`. |
| 61 | * The ordering of objects of type `Value` is a [*/strict weak ordering/], as defined in the `LessThanComparableConcept` requirements. |
| 62 | * `ForwardRange`'s value type is the same type as `Value`. |
| 63 | |
| 64 | [*For the predicate versions:] |
| 65 | |
| 66 | * `ForwardRange` is a model of the __forward_range__ Concept. |
| 67 | * `SortPredicate` is a model of the `StrictWeakOrderingConcept`. |
| 68 | * `ForwardRange`'s value type is the same as `Value`. |
| 69 | * `ForwardRange`'s value type is convertible to both of `SortPredicate`'s argument types. |
| 70 | |
| 71 | [heading Precondition:] |
| 72 | |
| 73 | For the non-predicate versions: `rng` is ordered in ascending order according to `operator<`. |
| 74 | |
| 75 | For the predicate versions: `rng` is ordered in ascending order according to `pred`. |
| 76 | |
| 77 | [heading Complexity] |
| 78 | |
| 79 | For random-access ranges, the complexity is `O(log N)`, otherwise the complexity is `O(N)`. |
| 80 | |
| 81 | [endsect] |
| 82 | |
| 83 | |