libs/range/doc/reference/algorithm/find_if.qbk
[/
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:find_if find_if]
[heading Prototype]
``
template<class SinglePassRange, class UnaryPredicate>
typename range_iterator<SinglePassRange>::type
find_if(SinglePassRange& rng, UnaryPredicate pred);
template<
range_return_value re,
class SinglePassRange,
class UnaryPredicate
>
typename range_return<SinglePassRange, re>::type
find_if(SinglePassRange& rng, UnaryPredicate pred);
``
[heading Description]
The versions of `find_if` that return an iterator, returns the first iterator in the range `rng` such that `pred(*i)` is `true`. `end(rng)` is returned if no such iterator exists.
The versions of `find_if` that return a `range_return`, defines found in the same manner as the returned iterator described above.
[heading Definition]
Defined in the header file `boost/range/algorithm/find_if.hpp`
[heading Requirements]
* `SinglePassRange` is a model of the __single_pass_range__ Concept.
* `UnaryPredicate` is a model of the `PredicateConcept`.
* The value type of `SinglePassRange` is convertible to the argument type of `UnaryPredicate`.
[heading Precondition:]
For each iterator `i` in `rng`, `*i` is in the domain of `UnaryPredicate`.
[heading Complexity]
Linear. At most `distance(rng)` invocations of `pred`.
[endsect]
