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authorVincent Ambo <mail@tazj.in>2020-07-15T07·20+0100
committerVincent Ambo <mail@tazj.in>2020-07-15T07·20+0100
commit7f19d641647ac4ef313ed88d6b5c140983ce5436 (patch)
tree31b66c81465293da5c093c5dde3e419758c0d6cc /extra/guile/scm/detail/pack.hpp
Squashed 'third_party/immer/' content from commit ad3e3556d
git-subtree-dir: third_party/immer
git-subtree-split: ad3e3556d38bb75966dd24c61a774970a7c7957e
Diffstat (limited to 'extra/guile/scm/detail/pack.hpp')
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diff --git a/extra/guile/scm/detail/pack.hpp b/extra/guile/scm/detail/pack.hpp
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+//
+// 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 scm {
+namespace detail {
+
+struct none_t;
+
+template <typename... Ts>
+struct pack {};
+
+template <typename Pack>
+struct pack_size;
+
+template <typename... Ts>
+struct pack_size<pack<Ts...>>
+{
+    static constexpr auto value = sizeof...(Ts);
+};
+
+template <typename Pack>
+constexpr auto pack_size_v = pack_size<Pack>::value;
+
+template <typename Pack>
+struct pack_last
+{
+    using type = none_t;
+};
+
+template <typename T, typename ...Ts>
+struct pack_last<pack<T, Ts...>>
+    : pack_last<pack<Ts...>>
+{};
+
+template <typename T>
+struct pack_last<pack<T>>
+{
+    using type = T;
+};
+
+template <typename Pack>
+using pack_last_t = typename pack_last<Pack>::type;
+
+} // namespace detail
+} // namespace scm