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- [#token]
- [section token]
- [h1 Synopsis]
- template <class P>
- struct token;
- This is a [link parser_combinator parser combinator].
- [table Arguments
- [[Name] [Type]]
- [[`P`] [[link parser parser]]]
- ]
- [h1 Description]
- `token` parses the input using `P` when it succeeds, `token` consumes all
- whitespaces afterwards. The result of parsing is the result of `P`.
- [h1 Header]
- #include <boost/metaparse/token.hpp>
- [h1 Expression semantics]
- For any `p` parser the following are equivalent:
- token<p>
-
- first_of<p, spaces>
- [h1 Example]
- #include <boost/metaparse/token.hpp>
- #include <boost/metaparse/int_.hpp>
- #include <boost/metaparse/start.hpp>
- #include <boost/metaparse/get_result.hpp>
- #include <boost/metaparse/get_remaining.hpp>
- #include <boost/metaparse/is_error.hpp>
- #include <boost/metaparse/string.hpp>
-
- #include <type_traits>
-
- using namespace boost::metaparse;
-
- using int_token = token<int_>;
-
- static_assert(
- get_result<
- int_token::apply<BOOST_METAPARSE_STRING("13 "), start>
- >::type::value,
- "the result of int_token is the number"
- );
-
- static_assert(
- std::is_same<
- BOOST_METAPARSE_STRING(""),
- get_remaining<int_token::apply<BOOST_METAPARSE_STRING("13 "), start>>::type
- >::type::value,
- "token consumes whitespaces after the number"
- );
-
- static_assert(
- get_result<
- int_token::apply<BOOST_METAPARSE_STRING("13"), start>
- >::type::value,
- "whitespaces after the number are optional"
- );
-
- static_assert(
- is_error<int_token::apply<BOOST_METAPARSE_STRING("foo"), start>>::type::value,
- "when there is no number, token fails"
- );
- [endsect]
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