diff options
Diffstat (limited to 'paludis/util/hashes.hh')
| -rw-r--r-- | paludis/util/hashes.hh | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/paludis/util/hashes.hh b/paludis/util/hashes.hh index c77681979..5d74eed79 100644 --- a/paludis/util/hashes.hh +++ b/paludis/util/hashes.hh @@ -1,7 +1,7 @@ /* vim: set sw=4 sts=4 et foldmethod=syntax : */ /* - * Copyright (c) 2008, 2010 Ciaran McCreesh + * Copyright (c) 2008, 2010, 2011 Ciaran McCreesh * * This file is part of the Paludis package manager. Paludis is free software; * you can redistribute it and/or modify it under the terms of the GNU General @@ -24,6 +24,7 @@ #include <paludis/util/wrapped_value-fwd.hh> #include <paludis/util/fs_path-fwd.hh> #include <cstddef> +#include <tuple> #include <utility> #include <string> #include <type_traits> @@ -83,6 +84,43 @@ namespace paludis } }; + template <unsigned n_, typename... Keys_> + std::size_t single_tuple_hash(const std::tuple<Keys_...> & p) + { + return Hash<typename std::tuple_element<n_, std::tuple<Keys_...> >::type>()(std::get<n_>(p)); + } + + struct FinishedHashingTuple + { + }; + + struct NotFinishedHashingTuple + { + }; + + template <unsigned n_, typename... Keys_> + std::size_t accumulate_tuple_hash(const std::tuple<Keys_...> &, std::size_t v, const FinishedHashingTuple &) + { + return v; + } + + template <unsigned n_, typename... Keys_> + std::size_t accumulate_tuple_hash(const std::tuple<Keys_...> & p, std::size_t v, const NotFinishedHashingTuple &) + { + return accumulate_tuple_hash<n_ + 1, Keys_...>(p, (v << 8) ^ single_tuple_hash<n_>(p), + typename std::conditional<std::tuple_size<std::tuple<Keys_...> >::value == n_ + 1, + FinishedHashingTuple, NotFinishedHashingTuple>::type()); + } + + template <typename... Keys_> + struct Hash<std::tuple<Keys_...> > + { + std::size_t operator() (const std::tuple<Keys_...> & p) const + { + return accumulate_tuple_hash<0, Keys_...>(p, 0, NotFinishedHashingTuple()); + } + }; + template <typename Tag_> struct Hash<WrappedValue<Tag_> > { |