projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | .. Metafunctions/String Operations//c_str |10 |
| 2 | ||
| 3 | ||
| 4 | c_str | |
| 5 | ===== | |
| 6 | ||
| 7 | Synopsis | |
| 8 | -------- | |
| 9 | ||
| 10 | .. parsed-literal:: | |
| 11 | ||
| 12 | template< | |
| 13 | typename Sequence | |
| 14 | > | |
| 15 | struct c_str | |
| 16 | { | |
| 17 | typedef |unspecified| type; | |
| 18 | static char const value[]; | |
| 19 | }; | |
| 20 | ||
| 21 | ||
| 22 | Description | |
| 23 | ----------- | |
| 24 | ||
| 25 | ``c_str`` converts the |Forward Sequence| of |Integral Constant|\ s ``Sequence`` | |
| 26 | into a null-terminated byte string containing an equivalent sequence. | |
| 27 | ||
| 28 | ||
| 29 | Header | |
| 30 | ------ | |
| 31 | ||
| 32 | .. parsed-literal:: | |
| 33 | ||
| 34 | #include <boost/mpl/string.hpp> | |
| 35 | ||
| 36 | ||
| 37 | Model of | |
| 38 | -------- | |
| 39 | ||
| 40 | |Metafunction| | |
| 41 | ||
| 42 | ||
| 43 | Parameters | |
| 44 | ---------- | |
| 45 | ||
| 46 | +---------------+---------------------------+-----------------------------------------------+ | |
| 47 | | Parameter | Requirement | Description | | |
| 48 | +===============+===========================+===============================================+ | |
| 49 | | ``Sequence`` | |Forward Sequence| of | A sequence to be converted into a | | |
| 50 | | | |Integral Constant|\ s | null-terminated byte string. | | |
| 51 | +---------------+---------------------------+-----------------------------------------------+ | |
| 52 | ||
| 53 | ||
| 54 | Expression semantics | |
| 55 | -------------------- | |
| 56 | ||
| 57 | .. compound:: | |
| 58 | :class: expression-semantics | |
| 59 | ||
| 60 | For any |Forward Sequence| of |Integral Constant|\ s ``s``, | |
| 61 | ||
| 62 | .. parsed-literal:: | |
| 63 | ||
| 64 | c_str<s>::value; | |
| 65 | ||
| 66 | :Return type: | |
| 67 | A null-terminated byte string. | |
| 68 | ||
| 69 | :Precondition: | |
| 70 | ``size<s>::value <= BOOST_MPL_STRING_MAX_LENGTH``. | |
| 71 | ||
| 72 | :Semantics: | |
| 73 | Equivalent to | |
| 74 | ||
| 75 | .. parsed-literal:: | |
| 76 | ||
| 77 | char const value[] = { | |
| 78 | at<s, 0>::type::value | |
| 79 | , ... | |
| 80 | , at<s, size<s>::value-1>::type::value | |
| 81 | , '\\0' | |
| 82 | }; | |
| 83 | ||
| 84 | Complexity | |
| 85 | ---------- | |
| 86 | ||
| 87 | +-------------------------------+-----------------------------------+ | |
| 88 | | Sequence archetype | Complexity | | |
| 89 | +===============================+===================================+ | |
| 90 | | |Forward Sequence| | Linear. | | |
| 91 | +-------------------------------+-----------------------------------+ | |
| 92 | ||
| 93 | Example | |
| 94 | ------- | |
| 95 | ||
| 96 | .. parsed-literal:: | |
| 97 | ||
| 98 | typedef vector_c<char,'h','e','l','l','o'> hello; | |
| 99 | assert( 0 == std::strcmp( c_str<hello>::value, "hello" ) ); | |
| 100 | ||
| 101 | See also | |
| 102 | -------- | |
| 103 | ||
| 104 | |Forward Sequence|, |Integral Constant|, |string| | |
| 105 | ||
| 106 | ||
| 107 |