mirror of
https://github.com/matrix-construct/construct
synced 2024-11-26 08:42:34 +01:00
164 lines
3.1 KiB
C++
164 lines
3.1 KiB
C++
// Matrix Construct
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//
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// Copyright (C) Matrix Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
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//
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// Permission to use, copy, modify, and/or distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice is present in all copies. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_JSON_TUPLE_AT_H
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namespace ircd {
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namespace json {
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template<size_t hash,
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class tuple>
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inline enable_if_tuple<tuple, const tuple_value_type<tuple, indexof<tuple, hash>()> &>
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at(const tuple &t)
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{
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constexpr size_t idx
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{
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indexof<tuple, hash>()
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};
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const auto &ret
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{
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val<idx>(t)
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};
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if(unlikely(!defined(json::value(ret))))
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throw not_found
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{
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"%s", key<idx>(t)
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};
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return ret;
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}
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template<size_t hash,
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class tuple>
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inline enable_if_tuple<tuple, tuple_value_type<tuple, indexof<tuple, hash>()> &>
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at(tuple &t)
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{
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constexpr size_t idx
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{
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indexof<tuple, hash>()
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};
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auto &ret
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{
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val<idx>(t)
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};
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if(unlikely(!defined(json::value(ret))))
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throw not_found
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{
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"%s", key<idx>(t)
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};
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return ret;
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}
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template<const char *const &name,
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class tuple>
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inline enable_if_tuple<tuple, const tuple_value_type<tuple, indexof<tuple, name>()> &>
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at(const tuple &t)
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{
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return at<name_hash(name), tuple>(t);
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}
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template<const char *const &name,
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class tuple>
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inline enable_if_tuple<tuple, tuple_value_type<tuple, indexof<tuple, name>()> &>
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at(tuple &t)
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{
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return at<name_hash(name), tuple>(t);
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}
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template<class tuple,
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class function,
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size_t i = 0>
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inline enable_if_tuple<tuple, void>
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at(tuple &t,
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const string_view &name,
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function&& f)
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{
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if constexpr(i < size<tuple>())
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{
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if(_constexpr_equal(name, key<tuple, i>()))
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f(val<i>(t));
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else
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at<tuple, function, i + 1>(t, name, std::forward<function>(f));
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}
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else throw not_found
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{
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"%s", name
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};
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}
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template<class tuple,
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class function,
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size_t i = 0>
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inline enable_if_tuple<tuple, void>
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at(const tuple &t,
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const string_view &name,
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function&& f)
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{
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if constexpr(i < size<tuple>())
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{
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if(_constexpr_equal(name, key<tuple, i>()))
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f(val<i>(t));
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else
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at<tuple, function, i + 1>(t, name, std::forward<function>(f));
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}
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else throw not_found
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{
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"%s", name
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};
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}
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template<class R,
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class tuple>
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inline enable_if_tuple<tuple, const R &>
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at(const tuple &t,
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const string_view &name)
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{
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const R *ret;
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at(t, name, [&ret](auto&& val) noexcept
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{
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//XXX is_pointer_interconvertible_base_of? (C++20)
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if constexpr(std::is_assignable<R, decltype(val)>())
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ret = std::addressof(val);
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else
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assert(false);
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});
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return *ret;
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}
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template<class R,
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class tuple>
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inline enable_if_tuple<tuple, R &>
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at(tuple &t,
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const string_view &name)
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{
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R *ret;
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at(t, name, [&ret]
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(auto &val)
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noexcept
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{
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//XXX is_pointer_interconvertible_base_of? (C++20)
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if constexpr(std::is_assignable<R, decltype(val)>())
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ret = std::addressof(val);
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else
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assert(false);
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});
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return *ret;
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}
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} // namespace json
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} // namespace ircd
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