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Diffstat (limited to '')
-rw-r--r-- | third_party/immer/extra/guile/scm/detail/pack.hpp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/third_party/immer/extra/guile/scm/detail/pack.hpp b/third_party/immer/extra/guile/scm/detail/pack.hpp new file mode 100644 index 000000000000..9a1813570bcd --- /dev/null +++ b/third_party/immer/extra/guile/scm/detail/pack.hpp @@ -0,0 +1,52 @@ +// +// 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 |