45 lines
1.3 KiB
C++
45 lines
1.3 KiB
C++
/*
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This file is part of Telegram Desktop,
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the official desktop application for the Telegram messaging service.
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For license and copyright information please follow this link:
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https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
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*/
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#pragma once
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#include <mapbox/variant.hpp>
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// We use base::variant<> alias and base::get_if() helper while we don't have std::variant<>.
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namespace base {
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template <typename... Types>
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using variant = mapbox::util::variant<Types...>;
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template <typename T, typename... Types>
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inline T *get_if(variant<Types...> *v) {
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return (v && v->template is<T>()) ? &v->template get_unchecked<T>() : nullptr;
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}
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template <typename T, typename... Types>
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inline const T *get_if(const variant<Types...> *v) {
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return (v && v->template is<T>()) ? &v->template get_unchecked<T>() : nullptr;
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}
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// Simplified visit
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template <typename Method, typename... Types>
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inline auto visit(Method &&method, const variant<Types...> &value) {
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return value.match(std::forward<Method>(method));
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}
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template <typename Method, typename... Types>
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inline auto visit(Method &&method, variant<Types...> &value) {
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return value.match(std::forward<Method>(method));
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}
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template <typename Method, typename... Types>
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inline auto visit(Method &&method, variant<Types...> &&value) {
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return value.match(std::forward<Method>(method));
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}
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} // namespace base
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