3 Forward declares `boost::hana::erase_key`.
5 @copyright Louis Dionne 2013-2016
6 Distributed under the Boost Software License, Version 1.0.
7 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
10 #ifndef BOOST_HANA_FWD_ERASE_KEY_HPP
11 #define BOOST_HANA_FWD_ERASE_KEY_HPP
13 #include <boost/hana/config.hpp>
14 #include <boost/hana/core/when.hpp>
17 BOOST_HANA_NAMESPACE_BEGIN
18 // Note: This function is documented per datatype/concept only.
20 template <typename T, typename = void>
21 struct erase_key_impl : erase_key_impl<T, when<true>> { };
25 template <typename Set, typename ...Args>
26 constexpr decltype(auto) operator()(Set&& set, Args&& ...args) const;
29 constexpr erase_key_t erase_key{};
30 BOOST_HANA_NAMESPACE_END
32 #endif // !BOOST_HANA_FWD_ERASE_KEY_HPP