12345678910111213141516171819202122232425262728293031 |
- #ifndef BOOST_HANA_CONCEPT_FOLDABLE_HPP
- #define BOOST_HANA_CONCEPT_FOLDABLE_HPP
- #include <boost/hana/fwd/concept/foldable.hpp>
- #include <boost/hana/config.hpp>
- #include <boost/hana/core/default.hpp>
- #include <boost/hana/core/tag_of.hpp>
- #include <boost/hana/fold_left.hpp>
- #include <boost/hana/unpack.hpp>
- BOOST_HANA_NAMESPACE_BEGIN
- template <typename T>
- struct Foldable {
- using Tag = typename tag_of<T>::type;
- static constexpr bool value = !is_default<fold_left_impl<Tag>>::value ||
- !is_default<unpack_impl<Tag>>::value;
- };
- BOOST_HANA_NAMESPACE_END
- #endif
|