projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | .. Sequences/Views//single_view |
| 2 | ||
| 3 | single_view | |
| 4 | =========== | |
| 5 | ||
| 6 | Synopsis | |
| 7 | -------- | |
| 8 | ||
| 9 | .. parsed-literal:: | |
| 10 | ||
| 11 | template< | |
| 12 | typename T | |
| 13 | > | |
| 14 | struct single_view | |
| 15 | { | |
| 16 | // |unspecified| | |
| 17 | // |...| | |
| 18 | }; | |
| 19 | ||
| 20 | ||
| 21 | ||
| 22 | Description | |
| 23 | ----------- | |
| 24 | ||
| 25 | A view onto an arbitrary type ``T`` as on a single-element sequence. | |
| 26 | ||
| 27 | ||
| 28 | Header | |
| 29 | ------ | |
| 30 | ||
| 31 | .. parsed-literal:: | |
| 32 | ||
| 33 | #include <boost/mpl/single_view.hpp> | |
| 34 | ||
| 35 | ||
| 36 | Model of | |
| 37 | -------- | |
| 38 | ||
| 39 | * |Random Access Sequence| | |
| 40 | ||
| 41 | ||
| 42 | Parameters | |
| 43 | ---------- | |
| 44 | ||
| 45 | +---------------+-------------------+-----------------------------------------------+ | |
| 46 | | Parameter | Requirement | Description | | |
| 47 | +===============+===================+===============================================+ | |
| 48 | | ``T`` | Any type | The type to be wrapped in a sequence. | | |
| 49 | +---------------+-------------------+-----------------------------------------------+ | |
| 50 | ||
| 51 | ||
| 52 | Expression semantics | |
| 53 | -------------------- | |
| 54 | ||
| 55 | |Semantics disclaimer...| |Random Access Sequence|. | |
| 56 | ||
| 57 | In the following table, ``v`` is an instance of ``single_view``, ``x`` is an arbitrary type. | |
| 58 | ||
| 59 | +-------------------------------+-----------------------------------------------------------+ | |
| 60 | | Expression | Semantics | | |
| 61 | +===============================+===========================================================+ | |
| 62 | | .. parsed-literal:: | A single-element |Random Access Sequence| ``v`` such that | | |
| 63 | | | ``front<v>::type`` is identical to ``x``. | | |
| 64 | | single_view<x> | | | |
| 65 | | single_view<x>::type | | | |
| 66 | +-------------------------------+-----------------------------------------------------------+ | |
| 67 | | ``size<v>::type`` | The size of ``v``; ``size<v>::value == 1``; | | |
| 68 | | | see |Random Access Sequence|. | | |
| 69 | +-------------------------------+-----------------------------------------------------------+ | |
| 70 | ||
| 71 | Example | |
| 72 | ------- | |
| 73 | ||
| 74 | .. parsed-literal:: | |
| 75 | ||
| 76 | typedef single_view<int> view; | |
| 77 | typedef begin<view>::type first; | |
| 78 | typedef end<view>::type last; | |
| 79 | ||
| 80 | BOOST_MPL_ASSERT(( is_same< deref<first>::type,int > )); | |
| 81 | BOOST_MPL_ASSERT(( is_same< next<first>::type,last > )); | |
| 82 | BOOST_MPL_ASSERT(( is_same< prior<last>::type,first > )); | |
| 83 | ||
| 84 | BOOST_MPL_ASSERT_RELATION( size<view>::value, ==, 1 ); | |
| 85 | ||
| 86 | ||
| 87 | See also | |
| 88 | -------- | |
| 89 | ||
| 90 | |Sequences|, |Views|, |iterator_range|, |filter_view|, |transform_view|, |joint_view|, |zip_view| | |
| 91 | ||
| 92 | ||
| 93 |