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Diffstat (limited to 'immer/transience/no_transience_policy.hpp')
-rw-r--r-- | immer/transience/no_transience_policy.hpp | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/immer/transience/no_transience_policy.hpp b/immer/transience/no_transience_policy.hpp new file mode 100644 index 000000000000..2f87df7a39b0 --- /dev/null +++ b/immer/transience/no_transience_policy.hpp @@ -0,0 +1,48 @@ +// +// immer: immutable data structures for C++ +// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente +// +// This software is distributed under the Boost Software License, Version 1.0. +// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt +// + +#pragma once + +namespace immer { + +/*! + * Disables any special *transience* tracking. To be used when + * *reference counting* is available instead. + */ +struct no_transience_policy +{ + template <typename> + struct apply + { + struct type + { + struct edit + {}; + + struct owner + { + operator edit() const { return {}; } + }; + + struct ownee + { + ownee& operator=(edit) { return *this; }; + bool can_mutate(edit) const { return false; } + bool owned() const { return false; } + }; + + static owner noone; + }; + }; +}; + +template <typename HP> +typename no_transience_policy::apply<HP>::type::owner + no_transience_policy::apply<HP>::type::noone = {}; + +} // namespace immer |