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[/ File none_of.qbk]
[section:none_of none_of]
[/license
Copyright (c) 2010-2012 Marshall Clow
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)
]
The header file 'boost/algorithm/cxx11/none_of.hpp' contains four variants of a single algorithm, `none_of`. The algorithm tests all the elements of a sequence and returns true if they none of them share a property.
The routine `none_of` takes a sequence and a predicate. It will return true if the predicate returns false when applied to every element in the sequence.
The routine `none_of_equal` takes a sequence and a value. It will return true if none of the elements in the sequence compare equal to the passed in value.
Both routines come in two forms; the first one takes two iterators to define the range. The second form takes a single range parameter, and uses Boost.Range to traverse it.
[heading interface]
The function `none_of` returns true if the predicate returns false for every item in the sequence. There are two versions; one takes two iterators, and the other takes a range.
``
namespace boost { namespace algorithm {
template<typename InputIterator, typename Predicate>
bool none_of ( InputIterator first, InputIterator last, Predicate p );
template<typename Range, typename Predicate>
bool none_of ( const Range &r, Predicate p );
}}
``
The function `none_of_equal` is similar to `none_of`, but instead of taking a predicate to test the elements of the sequence, it takes a value to compare against.
``
namespace boost { namespace algorithm {
template<typename InputIterator, typename V>
bool none_of_equal ( InputIterator first, InputIterator last, V const &val );
template<typename Range, typename V>
bool none_of_equal ( const Range &r, V const &val );
}}
``
[heading Examples]
Given the container `c` containing `{ 0, 1, 2, 3, 14, 15 }`, then
``
bool isOdd ( int i ) { return i % 2 == 1; }
bool lessThan10 ( int i ) { return i < 10; }
using boost::algorithm;
none_of ( c, isOdd ) --> false
none_of ( c.begin (), c.end (), lessThan10 ) --> false
none_of ( c.begin () + 4, c.end (), lessThan10 ) --> true
none_of ( c.end (), c.end (), isOdd ) --> true // empty range
none_of_equal ( c, 3 ) --> false
none_of_equal ( c.begin (), c.begin () + 3, 3 ) --> true
none_of_equal ( c.begin (), c.begin (), 99 ) --> true // empty range
``
[heading Iterator Requirements]
`none_of` and `none_of_equal` work on all iterators except output iterators.
[heading Complexity]
All of the variants of `none_of` and `none_of_equal` run in ['O(N)] (linear) time; that is, they compare against each element in the list once. If any of the comparisons succeed, the algorithm will terminate immediately, without examining the remaining members of the sequence.
[heading Exception Safety]
All of the variants of `none_of` and `none_of_equal` take their parameters by value or const reference, and do not depend upon any global state. Therefore, all the routines in this file provide the strong exception guarantee.
[heading Notes]
* The routine `none_of` is part of the C++11 standard. When compiled using a C++11 implementation, the implementation from the standard library will be used.
* `none_of` and `none_of_equal` both return true for empty ranges, no matter what is passed to test against.
* The second parameter to `none_of_value` is a template parameter, rather than deduced from the first parameter (`std::iterator_traits<InputIterator>::value_type`) because that allows more flexibility for callers, and takes advantage of built-in comparisons for the type that is pointed to by the iterator. The function is defined to return true if, for all elements in the sequence, the expression `*iter == val` evaluates to false (where `iter` is an iterator to each element in the sequence)
[endsect]
[/ File none_of.qbk
Copyright 2011 Marshall Clow
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).
]
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