ceph/src/boost/libs/metaparse/doc/versioning.qbk

   1 [section Versioning]
   2
   3 This section describes how the library is prepared for supporting multiple
   4 (not backward compatible) changes.
   5
   6 [section Template classes]
   7
   8 The elements of the library are defined in the `boost::metaparse::v1`
   9 namespace. For example the `one_char` class is
  10 `boost::metaparse::v1::one_char` and is available after including the
  11 `<boost/metaparse/v1/one_char.hpp>` header file.
  12
  13 At the same time the library provides the `<boost/metaparse/one_char.hpp>`
  14 header file which includes `<boost/metaparse/v1/one_char.hpp>` and contains
  15 the following:
  16
  17   namespace boost
  18   {
  19     namespace metaparse
  20     {
  21       using v1::one_char;
  22     }
  23   }
  24
  25 This makes it possible to use `one_char` as `boost::metaparse::one_char`.
  26
  27 Future versions of the library may provide other namespaces (eg. `v2`). The
  28 header files in `<boost/metaparse/...>` provide the latest version of the
  29 library. To always get version `v1`, one should use header files in
  30 `<boost/metaparse/v1/...>`.
  31
  32 The library does not use inline namespaces to work on compilers that do not
  33 support them.
  34
  35 [endsect]
  36
  37 [section Macros]
  38
  39 Macros defined by the library are prefixed with `BOOST_METAPARSE_V1_`. For
  40 example `BOOST_METAPARSE_V1_STRING`. It is defined in the
  41 `<boost/metaparse/v1/string.hpp>` header file. The library provides the
  42 `<boost/metaparse/string.hpp>` header file as well, which includes the
  43 definition of this macro and provides the following definition:
  44
  45   #define BOOST_METAPARSE_STRING BOOST_METAPARSE_V1_STRING
  46
  47 This makes it possible to use the macro as `BOOST_METAPARSE_STRING`. Future
  48 versions of the library may define other versions of this macro (eg.
  49 `BOOST_METAPARSE_V2_STRING`). `BOOST_METAPARSE_STRING` will refer to the latest
  50 version.
  51
  52 This versioning does not affect macros that may be overridden by the code using
  53 the library. (eg. `BOOST_METAPARSE_LIMIT_STRING_SIZE`)
  54
  55 [endsect]
  56
  57 [endsect]
  58