.. Algorithms/Querying Algorithms//find |10

find

Synopsis

.. parsed-literal::

template<
      typename Sequence
    , typename T
    >
struct find
{
    typedef |unspecified| type;
};

Description

Returns an iterator to the first occurrence of type T in a Sequence.

Header

.. parsed-literal::

#include <boost/mpl/find.hpp>

Parameters

+---------------+-----------------------+-----------------------------------+ | Parameter | Requirement | Description | +===============+=======================+===================================+ | Sequence | |Forward Sequence| | A sequence to search in. | +---------------+-----------------------+-----------------------------------+ | T | Any type | A type to search for. | +---------------+-----------------------+-----------------------------------+

Expression semantics

For any |Forward Sequence| s and arbitrary type t:

.. parsed-literal::

typedef find<s,t>::type i;

:Return type: |Forward Iterator|.

:Semantics: Equivalent to

.. parsed-literal::

    typedef find_if<s, is_same<_,t> >::type i;

Complexity

Linear. At most size<s>::value comparisons for identity.

Example

.. parsed-literal::

typedef vector<char,int,unsigned,long,unsigned long> types;
typedef find<types,unsigned>::type iter;

BOOST_MPL_ASSERT(( is_same< deref<iter>::type, unsigned > ));
BOOST_MPL_ASSERT_RELATION( iter::pos::value, ==, 2 );

See also

|Querying Algorithms|, |contains|, |find_if|, |count|, |lower_bound|

.. copyright:: 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)