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The MPL Reference Manual: find_if
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find_if

Synopsis

template<
      typename Sequence
    , typename Pred
    >
struct find_if
{
    typedef unspecified type;
};

Description

Returns an iterator to the first element in Sequence that satisfies the predicate Pred.

Parameters

Parameter Requirement Description
Sequence Forward Sequence A sequence to search in.
Pred Unary Lambda Expression A search condition.

Expression semantics

For any Forward Sequence s and unary Lambda Expression pred:

typedef find_if::type i;
Return type:

Forward Iterator.
Semantics:

i is the first iterator in the range [begin::type, end::type) such that

apply< pred,deref::type >::type::value == true

If no such iterator exists, i is identical to end::type.

Complexity

Linear. At most size::value applications of pred.

Example

typedef vector types;
typedef find_if_1,unsigned> >::type iter;

BOOST_MPL_ASSERT(( is_same< deref::type, unsigned > ));
BOOST_MPL_ASSERT_RELATION( iter::pos::value, ==, 2 );
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Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams
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)