projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | .. Algorithms/Transformation Algorithms//reverse_copy_if |120 |
| 2 | ||
| 3 | reverse_copy_if | |
| 4 | =============== | |
| 5 | ||
| 6 | Synopsis | |
| 7 | -------- | |
| 8 | ||
| 9 | .. parsed-literal:: | |
| 10 | ||
| 11 | template< | |
| 12 | typename Sequence | |
| 13 | , typename Pred | |
| 14 | , typename In = |unspecified| | |
| 15 | > | |
| 16 | struct reverse_copy_if | |
| 17 | { | |
| 18 | typedef |unspecified| type; | |
| 19 | }; | |
| 20 | ||
| 21 | ||
| 22 | ||
| 23 | Description | |
| 24 | ----------- | |
| 25 | ||
| 26 | Returns a reversed, filtered copy of the original sequence containing the | |
| 27 | elements that satisfy the predicate ``Pred``. | |
| 28 | ||
| 29 | |transformation algorithm disclaimer| | |
| 30 | ||
| 31 | Header | |
| 32 | ------ | |
| 33 | ||
| 34 | .. parsed-literal:: | |
| 35 | ||
| 36 | #include <boost/mpl/copy_if.hpp> | |
| 37 | ||
| 38 | ||
| 39 | Model of | |
| 40 | -------- | |
| 41 | ||
| 42 | |Reversible Algorithm| | |
| 43 | ||
| 44 | ||
| 45 | Parameters | |
| 46 | ---------- | |
| 47 | ||
| 48 | +---------------+-----------------------------------+-------------------------------+ | |
| 49 | | Parameter | Requirement | Description | | |
| 50 | +===============+===================================+===============================+ | |
| 51 | | ``Sequence`` | |Forward Sequence| | A sequence to copy. | | |
| 52 | +---------------+-----------------------------------+-------------------------------+ | |
| 53 | | ``Pred`` | Unary |Lambda Expression| | A copying condition. | | |
| 54 | +---------------+-----------------------------------+-------------------------------+ | |
| 55 | | ``In`` | |Inserter| | An inserter. | | |
| 56 | +---------------+-----------------------------------+-------------------------------+ | |
| 57 | ||
| 58 | ||
| 59 | Expression semantics | |
| 60 | -------------------- | |
| 61 | ||
| 62 | |Semantics disclaimer...| |Reversible Algorithm|. | |
| 63 | ||
| 64 | For any |Forward Sequence| ``s``, an unary |Lambda Expression| ``pred``, and | |
| 65 | an |Inserter| ``in``: | |
| 66 | ||
| 67 | ||
| 68 | .. parsed-literal:: | |
| 69 | ||
| 70 | typedef reverse_copy_if<s,pred,in>::type r; | |
| 71 | ||
| 72 | ||
| 73 | :Return type: | |
| 74 | A type | |
| 75 | ||
| 76 | :Semantics: | |
| 77 | Equivalent to | |
| 78 | ||
| 79 | .. parsed-literal:: | |
| 80 | ||
| 81 | typedef lambda<pred>::type p; | |
| 82 | typedef lambda<in::operation>::type op; | |
| 83 | ||
| 84 | typedef reverse_fold< | |
| 85 | s | |
| 86 | , in::state | |
| 87 | , eval_if< | |
| 88 | apply_wrap\ ``1``\<p,_2> | |
| 89 | , apply_wrap\ ``2``\<op,_1,_2> | |
| 90 | , identity<_1> | |
| 91 | > | |
| 92 | >::type r; | |
| 93 | ||
| 94 | ||
| 95 | Complexity | |
| 96 | ---------- | |
| 97 | ||
| 98 | Linear. Exactly ``size<s>::value`` applications of ``pred``, and at | |
| 99 | most ``size<s>::value`` applications of ``in::operation``. | |
| 100 | ||
| 101 | ||
| 102 | Example | |
| 103 | ------- | |
| 104 | ||
| 105 | .. parsed-literal:: | |
| 106 | ||
| 107 | typedef reverse_copy_if< | |
| 108 | range_c<int,0,10> | |
| 109 | , less< _1, int_<5> > | |
| 110 | , front_inserter< vector<> > | |
| 111 | >::type result; | |
| 112 | ||
| 113 | BOOST_MPL_ASSERT_RELATION( size<result>::value, ==, 5 ); | |
| 114 | BOOST_MPL_ASSERT(( equal<result,range_c<int,0,5> > )); | |
| 115 | ||
| 116 | ||
| 117 | See also | |
| 118 | -------- | |
| 119 | ||
| 120 | |Transformation Algorithms|, |Reversible Algorithm|, |copy_if|, |reverse_copy|, |remove_if|, |replace_if| | |
| 121 | ||
| 122 | ||
| 123 |