metaparse/doc/lit_c.qbk
2015-07-19 09:53:35 +02:00

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[#lit_c]
[section lit_c]
[h1 Synopsis]
template <char C>
struct lit;
This is a [link parser parser].
[table Arguments
[[Name] [Type]]
[[`C`] [`char` value]]
]
[h1 Description]
Parser accepting only the `C` character. The result of parsing is the accepted
character.
[h1 Header]
#include <boost/metaparse/lit_c.hpp>
[h1 Expression semantics]
For any `c` character the following are equivalent:
lit_c<c>
lit<boost::mpl::char_<c>>
[h1 Example]
#include <boost/metaparse/lit_c.hpp>
#include <boost/metaparse/start.hpp>
#include <boost/metaparse/string.hpp>
#include <boost/metaparse/is_error.hpp>
#include <boost/metaparse/get_result.hpp>
using namespace boost::metaparse;
static_assert(
is_error<lit_c<'x'>::apply<BOOST_METAPARSE_STRING("a"), start>>::type::value,
"a different character should be an error"
);
static_assert(
is_error<lit_c<'x'>::apply<BOOST_METAPARSE_STRING(""), start>>::type::value,
"empty input should be an error"
);
static_assert(
get_result<
lit_c<'x'>::apply<BOOST_METAPARSE_STRING("x"), start>
>::type::value == 'x',
"result of parsing should be the accepted character"
);
[endsect]