[#int_]
[section int_]

[h1 Synopsis]

  struct int_;

This is a [link parser parser].

[h1 Description]

It accepts a non-empty sequence of characters in the range `0-9`. The result of
the parser is the decimal value represented by the accepted character sequence.

[h1 Header]

  #include <boost/metaparse/int_.hpp>

[h1 Expression semantics]

The following are equivalent:

  int_
  
  foldl1<
    digit_val,
    boost::mpl::int_<0>,
    boost::mpl::lambda<
      boost::mpl::plus<
        boost::mpl::times<boost::mpl::_2, boost::mpl::int_<10>>,
        boost::mpl::_1
      >
    >::type
  >

[h1 Example]

  #include <boost/metaparse/int_.hpp>
  #include <boost/metaparse/string.hpp>
  #include <boost/metaparse/start.hpp>
  #include <boost/metaparse/is_error.hpp>
  #include <boost/metaparse/get_result.hpp>
  
  using namespace boost::metaparse;
  
  static_assert(
    get_result<
      int_::apply<BOOST_METAPARSE_STRING("13"), start>
    >::type::value == 13,
    "It should parse an integer value"
  );
  
  static_assert(
    is_error<int_::apply<BOOST_METAPARSE_STRING("six"), start>>::type::value,
    "It should reject the input if it is not a number"
  );

[endsect]