EQ2EMu/EQ2/source/depends/boost_1_72_0/libs/metaparse/doc/space.qbk

[#space]
[section space]

[h1 Synopsis]

  struct space;

This is a [link parser parser].

[h1 Description]

`space` accepts one white space character. The result of parsing is the parsed
character.

[h1 Header]

  #include <boost/metaparse/space.hpp>

[h1 Expression semantics]

The following are equivalent:

  space
  
  accept_when<one_char, util::is_whitespace<>, errors::whitespace_expected>

[h1 Example]

  #include <boost/metaparse/space.hpp>
  #include <boost/metaparse/start.hpp>
  #include <boost/metaparse/string.hpp>
  #include <boost/metaparse/is_error.hpp>
  #include <boost/metaparse/get_remaining.hpp>
  
  #include <type_traits>
  
  using namespace boost::metaparse;
  
  static_assert(
    std::is_same<
      BOOST_METAPARSE_STRING(" foo"),
      get_remaining<space::apply<BOOST_METAPARSE_STRING("  foo"), start>>::type
    >::type::value,
    "it should consume the first space of the input"
  );
  
  static_assert(
    is_error<space::apply<BOOST_METAPARSE_STRING("x"), start>>::type::value,
    "it should return an error when the input does not begin with a whitespace"
  );

[endsect]