3 This section describes how the library is prepared for supporting multiple
4 (not backward compatible) changes.
6 [section Template classes]
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.
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
25 This makes it possible to use `one_char` as `boost::metaparse::one_char`.
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/...>`.
32 The library does not use inline namespaces to work on compilers that do not
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:
45 #define BOOST_METAPARSE_STRING BOOST_METAPARSE_V1_STRING
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
52 This versioning does not affect macros that may be overridden by the code using
53 the library. (eg. `BOOST_METAPARSE_LIMIT_STRING_SIZE`)