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- [#int_to_digit]
- [section int_to_digit]
- [h1 Synopsis]
- namespace util
- {
- template <class D>
- struct int_to_digit;
- }
- This is a [link lazy_metafunction lazy template metafunction] that supports
- [link currying currying].
- [table Arguments
- [[Name] [Type]]
- [[`D`] [[link boxed_value boxed] integer value]]
- ]
- [h1 Description]
- Converts a boxed integer value in the range `[0-9]` to a character representing
- that decimal value.
- [h1 Header]
- #include <boost/metaparse/util/int_to_digit.hpp>
- [h1 Expression semantics]
- The following pairs of expressions are equivalent
- int_to_digit<boost::mpl::int_<0>>::type
- boost::mpl::char_<'0'>
- int_to_digit<boost::mpl::int_<9>>::type
- boost::mpl::char_<'9'>
- [h1 Example]
- #include <boost/metaparse/util/int_to_digit.hpp>
-
- #include <type_traits>
-
- using namespace boost::metaparse;
-
- struct nullary_metafunction_returning_4
- {
- using type = std::integral_constant<int, 4>;
- };
-
- static_assert(
- util::int_to_digit<std::integral_constant<int, 0>>::type::value == '0',
- "it should convert an integer value to the corresponding character"
- );
-
- static_assert(
- util::int_to_digit<>::type
- ::apply<std::integral_constant<int, 7>>::type::value == '7',
- "it should support currying"
- );
-
- static_assert(
- util::int_to_digit<nullary_metafunction_returning_4>::type::value == '4',
- "it should support lazy evaluation"
- );
- [endsect]
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