| .. 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) |
