51 lines
1.5 KiB
C++
51 lines
1.5 KiB
C++
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/*!
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@file
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Forward declares `boost::hana::accessors`.
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@copyright Louis Dionne 2013-2016
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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*/
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#ifndef BOOST_HANA_FWD_ACCESSORS_HPP
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#define BOOST_HANA_FWD_ACCESSORS_HPP
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#include <boost/hana/config.hpp>
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#include <boost/hana/core/when.hpp>
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BOOST_HANA_NAMESPACE_BEGIN
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//! Returns a `Sequence` of pairs representing the accessors of the
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//! data structure.
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//! @ingroup group-Struct
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//!
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//! Given a `Struct` `S`, `accessors<S>()` is a `Sequence` of `Product`s
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//! where the first element of each pair is the "name" of a member of
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//! the `Struct`, and the second element of each pair is a function that
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//! can be used to access that member when given an object of the proper
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//! data type. As described in the global documentation for `Struct`, the
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//! accessor functions in this sequence must be move-independent.
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//!
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//!
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//! Example
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//! -------
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//! @include example/accessors.cpp
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#ifdef BOOST_HANA_DOXYGEN_INVOKED
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template <typename S>
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constexpr auto accessors = []() {
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return tag-dispatched;
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};
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#else
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template <typename S, typename = void>
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struct accessors_impl : accessors_impl<S, when<true>> { };
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template <typename S>
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struct accessors_t;
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template <typename S>
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constexpr accessors_t<S> accessors{};
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#endif
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BOOST_HANA_NAMESPACE_END
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#endif // !BOOST_HANA_FWD_ACCESSORS_HPP
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