| .. Algorithms/Transformation Algorithms//partition |85 |
| |
| partition |
| ========= |
| |
| Synopsis |
| -------- |
| |
| .. parsed-literal:: |
| |
| template< |
| typename Seq |
| , typename Pred |
| , typename In1 = |unspecified| |
| , typename In2 = |unspecified| |
| > |
| struct partition |
| { |
| typedef |unspecified| type; |
| }; |
| |
| |
| Description |
| ----------- |
| |
| Returns a pair of sequences together containing all elements in the range |
| |begin/end<Seq>| split into two groups based on the predicate ``Pred``. |
| ``partition`` is a synonym for |stable_partition|. |
| |
| |transformation algorithm disclaimer| |
| |
| |
| Header |
| ------ |
| |
| .. parsed-literal:: |
| |
| #include <boost/mpl/partition.hpp> |
| |
| |
| Model of |
| -------- |
| |
| |Reversible Algorithm| |
| |
| |
| Parameters |
| ---------- |
| |
| +-------------------+-----------------------------------+-------------------------------+ |
| | Parameter | Requirement | Description | |
| +===================+===================================+===============================+ |
| | ``Seq`` | |Forward Sequence| | An original sequence. | |
| +-------------------+-----------------------------------+-------------------------------+ |
| | ``Pred`` | Unary |Lambda Expression| | A partitioning predicate. | |
| +-------------------+-----------------------------------+-------------------------------+ |
| | ``In1``, ``In2`` | |Inserter| | Output inserters. | |
| +-------------------+-----------------------------------+-------------------------------+ |
| |
| |
| Expression semantics |
| -------------------- |
| |
| |Semantics disclaimer...| |Reversible Algorithm|. |
| |
| For any |Forward Sequence| ``s``, an unary |Lambda Expression| ``pred``, and |Inserter|\ s |
| ``in1`` and ``in2``: |
| |
| |
| .. parsed-literal:: |
| |
| typedef partition<s,pred,in1,in2>::type r; |
| |
| :Return type: |
| A |pair|. |
| |
| :Semantics: |
| Equivalent to |
| |
| .. parsed-literal:: |
| |
| typedef stable_partition<s,pred,in1,in2>::type r; |
| |
| |
| Complexity |
| ---------- |
| |
| Linear. Exactly ``size<s>::value`` applications of ``pred``, and ``size<s>::value`` |
| of summarized ``in1::operation`` / ``in2::operation`` applications. |
| |
| |
| Example |
| ------- |
| |
| .. parsed-literal:: |
| |
| template< typename N > struct is_odd : bool_<(N::value % 2)> {}; |
| |
| typedef partition< |
| range_c<int,0,10> |
| , is_odd<_1> |
| , back_inserter< vector<> > |
| , back_inserter< vector<> > |
| >::type r; |
| |
| BOOST_MPL_ASSERT(( equal< r::first, vector_c<int,1,3,5,7,9> > )); |
| BOOST_MPL_ASSERT(( equal< r::second, vector_c<int,0,2,4,6,8> > )); |
| |
| |
| See also |
| -------- |
| |
| |Transformation Algorithms|, |Reversible Algorithm|, |reverse_partition|, |stable_partition|, |sort| |
| |
| |
| .. 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) |
