123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051 |
- [#reject]
- [section reject]
- [h1 Synopsis]
- template <class Msg, class Pos>
- struct reject;
- This is a [link metaprogramming_value template metaprogramming value].
- [table Arguments
- [[Name] [Type]]
- [[`Msg`] [[link metaprogramming_value template metaprogramming value]]]
- [[`Pos`] [[link source_position source position]]]
- ]
- [h1 Description]
- Values representing a failed parser application. It behaves as a
- [link lazy_metafunction lazy template metafunction]: when it is evaluated as a
- metafunction, it returns itself with its arguments evaluated. See expression
- semantics for further details.
- [note
- Note that for backward compatibility when `Msg::type` is not defined,
- `reject<....>::type` does not evaluate `Msg`. For example
- `reject<int, start>::type` is `reject<int, start::type>`. Using types that are
- not template metaprogramming values as `Msg` is deprecated and will not work
- in future versions of the library.
- ]
- [h1 Expressions semantics]
- For any `m` template metaprogramming value and `p` source position the following
- are equivalent:
- reject<m, p>::type
-
- reject<m, p::type>
- [h1 Header]
- #include <boost/metaparse/reject.hpp>
- [h1 Operations]
- * [link get_position `get_position`]
- * [link get_message `get_message`]
- [endsect]
|