b1278b8e39
Pass adjust_iterator_dereference_type directly, instead of passing iterator_dereference_type and letting enumerated_iterator compute adjust_iterator_dereference_type.
35 lines
1.2 KiB
C++
35 lines
1.2 KiB
C++
/*
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* This file is part of the DXX-Rebirth project <http://www.dxx-rebirth.com/>.
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* It is copyright by its individual contributors, as recorded in the
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* project's Git history. See COPYING.txt at the top level for license
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* terms and a link to the Git history.
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*/
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#pragma once
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#include <cstddef>
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#include <type_traits>
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namespace detail {
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/* In the general case, a range is ephemeral if `T` is an rvalue reference,
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* since an rvalue may be moved or destroyed by the end of the statement.
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*/
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template <typename T>
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std::is_rvalue_reference<T> is_ephemeral_range(...);
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/* As a special exception to the general case, if the type T defines an inner
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* type `range_owns_iterated_storage`, delegate the test to that type. This
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* allows a type T to declare that it is only a view on longer-lived storage,
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* and therefore the storage is not ephemeral even when `T` is an rvalue
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* reference.
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*/
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template <typename T>
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typename std::remove_reference<T>::type::range_owns_iterated_storage is_ephemeral_range(std::nullptr_t);
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}
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/* Define a convenience helper that applies the `is_ephemeral_range` test to
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* any number of types.
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*/
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template <typename... Tn>
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using any_ephemeral_range = std::disjunction<decltype(detail::is_ephemeral_range<Tn>(nullptr))...>;
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