| 1234567891011121314151617181920212223242526272829 |
- /*!
- @file
- Defines `boost::hana::Constant`.
- @copyright Louis Dionne 2013-2016
- Distributed under the Boost Software License, Version 1.0.
- (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
- */
- #ifndef BOOST_HANA_CONCEPT_CONSTANT_HPP
- #define BOOST_HANA_CONCEPT_CONSTANT_HPP
- #include <boost/hana/fwd/concept/constant.hpp>
- #include <boost/hana/config.hpp>
- #include <boost/hana/core/default.hpp>
- #include <boost/hana/core/tag_of.hpp>
- #include <boost/hana/value.hpp>
- BOOST_HANA_NAMESPACE_BEGIN
- template <typename C>
- struct Constant {
- using Tag = typename tag_of<C>::type;
- static constexpr bool value = !is_default<value_impl<Tag>>::value;
- };
- BOOST_HANA_NAMESPACE_END
- #endif // !BOOST_HANA_CONCEPT_CONSTANT_HPP
|
