WSJT-X/boost/libs/range/doc/reference/algorithm/binary_search.qbk

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[/
Copyright 2010 Neil Groves
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
/]
[section:binary_search binary_search]
[heading Prototype]
``
template<class ForwardRange, class Value>
bool binary_search(const ForwardRange& rng, const Value& val);
template<class ForwardRange, class Value, class BinaryPredicate>
bool binary_search(const ForwardRange& rng, const Value& val, BinaryPredicate pred);
``
[heading Description]
`binary_search` returns `true` if and only if the value `val` exists in the range `rng`.
[heading Definition]
Defined in the header file `boost/range/algorithm/binary_search.hpp`
[heading Requirements]
[*For the non-predicate versions of binary_search:]
* `ForwardRange` is a model of the __forward_range__ Concept.
* `Value` is a model of the `LessThanComparableConcept`.
* The ordering of objects of type `Value` is a [*/strict weak ordering/], as defined in the `LessThanComparableConcept` requirements.
* `ForwardRange`'s value type is the same type as `Value`.
[*For the predicate versions of binary_search:]
* `ForwardRange` is a model of the __forward_range__ Concept.
* `BinaryPredicate` is a model of the `StrictWeakOrderingConcept`.
* `ForwardRange`'s value type is the same type as `Value`.
* `ForwardRange`'s value type is convertible to `BinaryPredicate`'s argument type.
[heading Precondition:]
[*For the non-predicate version:]
`rng` is ordered in ascending order according to `operator<`.
[*For the predicate version:]
`rng` is ordered in ascending order according to the function object `pred`.
[heading Complexity]
For non-random-access ranges, the complexity is `O(N)` where `N` is `distance(rng)`.
For random-access ranges, the complexity is `O(log N)` where `N` is `distance(rng)`.
[endsect]