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