Bug 1434710 - Removed mfbt/IndexSequence.h. r=botond draft
authorTom Bannister <tomabann@gmail.com>
Thu, 05 Apr 2018 17:10:50 +1000
changeset 778317 42b594da12bf00091fa126889a362b9d40c4eeba
parent 778316 00856ff9108e3575dd1b54ad1c8ad6a8877cf24f
push id105466
push userbmo:tomabann@gmail.com
push dateFri, 06 Apr 2018 06:41:20 +0000
reviewersbotond
bugs1434710
milestone61.0a1
Bug 1434710 - Removed mfbt/IndexSequence.h. r=botond MozReview-Commit-ID: Lly1I9qIcS0
mfbt/IndexSequence.h
deleted file mode 100644
--- a/mfbt/IndexSequence.h
+++ /dev/null
@@ -1,143 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/* A utility for expanding a tuple into a variadic argument list.
- * Based on std::index_sequence. */
-
-/**
- * Example usage:
- *
- * Problem:
- *
- *   You have a variadic function Foo:
- *
- *     template <typename... Args> void Foo(Args...);
- *
- *   And a variadic function Bar, which contains a tuple:
- *
- *     template <typename... Args>
- *     void Bar() {
- *       // ...
- *       Tuple<Args...> t;
- *     }
- *
- *   And inside Bar, you want to call Foo with the elements of the tuple as
- *   arguments to Foo.
- *
- *   You want to write:
- *
- *     Foo(Get<0>(t), Get<1>(t), ..., Get<N>(t))
- *
- *   but you can't literally write that, because N is different for different
- *   instantiations of Bar.
- *
- * Solution:
- *
- *   Write a helper function which takes the tuple, and an index sequence
- *   containing indices corresponding to the tuple indices.
- *
- *     template <typename... Args, size_t... Indices>
- *     void Helper(const Tuple<Args...>& t, IndexSequence<Indices...>)
- *     {
- *       Foo(Get<Indices>(t)...);
- *     }
- *
- *   Assuming 'Indices...' are 0, 1, ..., N - 1, where N is the size of the
- *   tuple, pack expansion will expand the pack 'Get<Indices>(t)...' to
- *   'Get<0>(t), Get<1>(t), ..., Get<N>(t)'.
- *
- *   Finally, call the helper, creating the index sequence to pass in like so:
- *
- *     template <typename... Args>
- *     void Bar() {
- *       // ...
- *       Tuple<Args...> t;
- *       Helper(t, typename IndexSequenceFor<Args...>::Type());
- *     }
- */
-
-#ifndef mozilla_IndexSequence_h
-#define mozilla_IndexSequence_h
-
-#include "mozilla/Attributes.h"
-
-#include <stddef.h>
-
-namespace mozilla {
-
-/**
- * Represents a compile-time sequence of integer indices.
- */
-template<size_t... Indices>
-struct IndexSequence
-{
-  static constexpr size_t Size() { return sizeof...(Indices); }
-};
-
-namespace detail {
-
-// Helpers used by MakeIndexSequence.
-
-template<size_t... Indices>
-struct IndexTuple
-{
-  typedef IndexTuple<Indices..., sizeof...(Indices)> Next;
-};
-
-// Builds IndexTuple<0, 1, ..., N - 1>.
-template<size_t N>
-struct BuildIndexTuple
-{
-  typedef typename BuildIndexTuple<N - 1>::Type::Next Type;
-};
-
-template<>
-struct BuildIndexTuple<0>
-{
-  typedef IndexTuple<> Type;
-};
-
-template<size_t N, typename IndexTuple>
-struct MakeIndexSequenceImpl;
-
-template<size_t N, size_t... Indices>
-struct MakeIndexSequenceImpl<N, IndexTuple<Indices...>>
-{
-  typedef IndexSequence<Indices...> Type;
-};
-
-} // namespace detail
-
-/**
- * A utility for building an IndexSequence of consecutive indices.
- * MakeIndexSequence<N>::Type evaluates to IndexSequence<0, 1, .., N - 1>.
- * Note: unlike std::make_index_sequence, this is not an alias template
- * to work around bugs in MSVC 2013.
- */
-template<size_t N>
-struct MakeIndexSequence
-{
-  typedef typename detail::MakeIndexSequenceImpl<N,
-    typename detail::BuildIndexTuple<N>::Type>::Type Type;
-};
-
-/**
- * A utility for building an IndexSequence of consecutive indices
- * corresponding to a variadic argument list.
- * IndexSequenceFor<Types...> evaluates to IndexSequence<0, 1, ..., N - 1>
- * where N is the number of types in Types.
- * Note: unlike std::index_sequence_for, this is not an alias template
- * to work around bugs in MSVC 2013.
- */
-template<typename... Types>
-struct IndexSequenceFor
-{
-  typedef typename MakeIndexSequence<sizeof...(Types)>::Type Type;
-};
-
-} // namespace mozilla
-
-#endif /* mozilla_IndexSequence_h */