projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | .. Sequences/Intrinsic Metafunctions//is_sequence |
| 2 | ||
| 3 | is_sequence | |
| 4 | =========== | |
| 5 | ||
| 6 | Synopsis | |
| 7 | -------- | |
| 8 | ||
| 9 | .. parsed-literal:: | |
| 10 | ||
| 11 | template< | |
| 12 | typename X | |
| 13 | > | |
| 14 | struct is_sequence | |
| 15 | { | |
| 16 | typedef |unspecified| type; | |
| 17 | }; | |
| 18 | ||
| 19 | ||
| 20 | ||
| 21 | Description | |
| 22 | ----------- | |
| 23 | ||
| 24 | Returns a boolean |Integral Constant| ``c`` such that ``c::value == true`` if and | |
| 25 | only if ``X`` is a model of |Forward Sequence|. | |
| 26 | ||
| 27 | ||
| 28 | Header | |
| 29 | ------ | |
| 30 | ||
| 31 | .. parsed-literal:: | |
| 32 | ||
| 33 | #include <boost/mpl/is_sequence.hpp> | |
| 34 | ||
| 35 | ||
| 36 | Parameters | |
| 37 | ---------- | |
| 38 | ||
| 39 | +---------------+-------------------+-----------------------------------------------+ | |
| 40 | | Parameter | Requirement | Description | | |
| 41 | +===============+===================+===============================================+ | |
| 42 | | ``X`` | Any type | The type to query. | | |
| 43 | +---------------+-------------------+-----------------------------------------------+ | |
| 44 | ||
| 45 | ||
| 46 | Expression semantics | |
| 47 | -------------------- | |
| 48 | ||
| 49 | ||
| 50 | .. parsed-literal:: | |
| 51 | ||
| 52 | typedef is_sequence<X>::type c; | |
| 53 | ||
| 54 | :Return type: | |
| 55 | Boolean |Integral Constant|. | |
| 56 | ||
| 57 | :Semantics: | |
| 58 | Equivalent to | |
| 59 | ||
| 60 | .. parsed-literal:: | |
| 61 | ||
| 62 | typedef not_< is_same< begin<T>::type,void_ > >::type c; | |
| 63 | ||
| 64 | ||
| 65 | ||
| 66 | Complexity | |
| 67 | ---------- | |
| 68 | ||
| 69 | Amortized constant time. | |
| 70 | ||
| 71 | ||
| 72 | Example | |
| 73 | ------- | |
| 74 | ||
| 75 | .. parsed-literal:: | |
| 76 | ||
| 77 | struct UDT {}; | |
| 78 | ||
| 79 | BOOST_MPL_ASSERT_NOT(( is_sequence< std::vector<int> > )); | |
| 80 | BOOST_MPL_ASSERT_NOT(( is_sequence< int > )); | |
| 81 | BOOST_MPL_ASSERT_NOT(( is_sequence< int& > )); | |
| 82 | BOOST_MPL_ASSERT_NOT(( is_sequence< UDT > )); | |
| 83 | BOOST_MPL_ASSERT_NOT(( is_sequence< UDT* > )); | |
| 84 | BOOST_MPL_ASSERT(( is_sequence< range_c<int,0,0> > )); | |
| 85 | BOOST_MPL_ASSERT(( is_sequence< list<> > )); | |
| 86 | BOOST_MPL_ASSERT(( is_sequence< list<int> > )); | |
| 87 | BOOST_MPL_ASSERT(( is_sequence< vector<> > )); | |
| 88 | BOOST_MPL_ASSERT(( is_sequence< vector<int> > )); | |
| 89 | ||
| 90 | ||
| 91 | See also | |
| 92 | -------- | |
| 93 | ||
| 94 | |Forward Sequence|, |begin|, |end|, |vector|, |list|, |range_c| | |
| 95 | ||
| 96 | ||
| 97 |