Move base to DEPS

base/tuple.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// A Tuple is a generic templatized container, similar in concept to std::pair
-// and std::tuple.  The convenient MakeTuple() function takes any number of
-// arguments and will construct and return the appropriate Tuple object.  The
-// functions DispatchToMethod and DispatchToFunction take a function pointer or
-// instance and method pointer, and unpack a tuple into arguments to the call.
-//
-// Tuple elements are copied by value, and stored in the tuple.  See the unit
-// tests for more details of how/when the values are copied.
-//
-// Example usage:
-//   // These two methods of creating a Tuple are identical.
-//   Tuple<int, const char*> tuple_a(1, "wee");
-//   Tuple<int, const char*> tuple_b = MakeTuple(1, "wee");
-//
-//   void SomeFunc(int a, const char* b) { }
-//   DispatchToFunction(&SomeFunc, tuple_a);  // SomeFunc(1, "wee")
-//   DispatchToFunction(
-//       &SomeFunc, MakeTuple(10, "foo"));    // SomeFunc(10, "foo")
-//
-//   struct { void SomeMeth(int a, int b, int c) { } } foo;
-//   DispatchToMethod(&foo, &Foo::SomeMeth, MakeTuple(1, 2, 3));
-//   // foo->SomeMeth(1, 2, 3);
-
-#ifndef BASE_TUPLE_H_
-#define BASE_TUPLE_H_
-
-#include "base/bind_helpers.h"
-
-namespace base {
-
-// Index sequences
-//
-// Minimal clone of the similarly-named C++14 functionality.
-
-template <size_t...>
-struct IndexSequence {};
-
-template <size_t... Ns>
-struct MakeIndexSequenceImpl;
-
-#if defined(_PREFAST_) && defined(OS_WIN)
-
-// Work around VC++ 2013 /analyze internal compiler error:
-// https://connect.microsoft.com/VisualStudio/feedback/details/1053626
-
-template <> struct MakeIndexSequenceImpl<0> {
-  using Type = IndexSequence<>;
-};
-template <> struct MakeIndexSequenceImpl<1> {
-  using Type = IndexSequence<0>;
-};
-template <> struct MakeIndexSequenceImpl<2> {
-  using Type = IndexSequence<0,1>;
-};
-template <> struct MakeIndexSequenceImpl<3> {
-  using Type = IndexSequence<0,1,2>;
-};
-template <> struct MakeIndexSequenceImpl<4> {
-  using Type = IndexSequence<0,1,2,3>;
-};
-template <> struct MakeIndexSequenceImpl<5> {
-  using Type = IndexSequence<0,1,2,3,4>;
-};
-template <> struct MakeIndexSequenceImpl<6> {
-  using Type = IndexSequence<0,1,2,3,4,5>;
-};
-template <> struct MakeIndexSequenceImpl<7> {
-  using Type = IndexSequence<0,1,2,3,4,5,6>;
-};
-template <> struct MakeIndexSequenceImpl<8> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7>;
-};
-template <> struct MakeIndexSequenceImpl<9> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7,8>;
-};
-template <> struct MakeIndexSequenceImpl<10> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7,8,9>;
-};
-template <> struct MakeIndexSequenceImpl<11> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7,8,9,10>;
-};
-template <> struct MakeIndexSequenceImpl<12> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7,8,9,10,11>;
-};
-template <> struct MakeIndexSequenceImpl<13> {
-  using Type = IndexSequence<0,1,2,3,4,5,6,7,8,9,10,11,12>;
-};
-
-#else  // defined(WIN) && defined(_PREFAST_)
-
-template <size_t... Ns>
-struct MakeIndexSequenceImpl<0, Ns...> {
-  using Type = IndexSequence<Ns...>;
-};
-
-template <size_t N, size_t... Ns>
-struct MakeIndexSequenceImpl<N, Ns...>
-    : MakeIndexSequenceImpl<N - 1, N - 1, Ns...> {};
-
-#endif  // defined(WIN) && defined(_PREFAST_)
-
-template <size_t N>
-using MakeIndexSequence = typename MakeIndexSequenceImpl<N>::Type;
-
-// Traits ----------------------------------------------------------------------
-//
-// A simple traits class for tuple arguments.
-//
-// ValueType: the bare, nonref version of a type (same as the type for nonrefs).
-// RefType: the ref version of a type (same as the type for refs).
-// ParamType: what type to pass to functions (refs should not be constified).
-
-template <class P>
-struct TupleTraits {
-  typedef P ValueType;
-  typedef P& RefType;
-  typedef const P& ParamType;
-};
-
-template <class P>
-struct TupleTraits<P&> {
-  typedef P ValueType;
-  typedef P& RefType;
-  typedef P& ParamType;
-};
-
-// Tuple -----------------------------------------------------------------------
-//
-// This set of classes is useful for bundling 0 or more heterogeneous data types
-// into a single variable.  The advantage of this is that it greatly simplifies
-// function objects that need to take an arbitrary number of parameters; see
-// RunnableMethod and IPC::MessageWithTuple.
-//
-// Tuple<> is supplied to act as a 'void' type.  It can be used, for example,
-// when dispatching to a function that accepts no arguments (see the
-// Dispatchers below).
-// Tuple<A> is rarely useful.  One such use is when A is non-const ref that you
-// want filled by the dispatchee, and the tuple is merely a container for that
-// output (a "tier").  See MakeRefTuple and its usages.
-
-template <typename IxSeq, typename... Ts>
-struct TupleBaseImpl;
-template <typename... Ts>
-using TupleBase = TupleBaseImpl<MakeIndexSequence<sizeof...(Ts)>, Ts...>;
-template <size_t N, typename T>
-struct TupleLeaf;
-
-template <typename... Ts>
-struct Tuple : TupleBase<Ts...> {
-  Tuple() : TupleBase<Ts...>() {}
-  explicit Tuple(typename TupleTraits<Ts>::ParamType... args)
-      : TupleBase<Ts...>(args...) {}
-};
-
-// Avoids ambiguity between Tuple's two constructors.
-template <>
-struct Tuple<> {};
-
-template <size_t... Ns, typename... Ts>
-struct TupleBaseImpl<IndexSequence<Ns...>, Ts...> : TupleLeaf<Ns, Ts>... {
-  TupleBaseImpl() : TupleLeaf<Ns, Ts>()... {}
-  explicit TupleBaseImpl(typename TupleTraits<Ts>::ParamType... args)
-      : TupleLeaf<Ns, Ts>(args)... {}
-};
-
-template <size_t N, typename T>
-struct TupleLeaf {
-  TupleLeaf() {}
-  explicit TupleLeaf(typename TupleTraits<T>::ParamType x) : x(x) {}
-
-  T& get() { return x; }
-  const T& get() const { return x; }
-
-  T x;
-};
-
-// Tuple getters --------------------------------------------------------------
-//
-// Allows accessing an arbitrary tuple element by index.
-//
-// Example usage:
-//   base::Tuple<int, double> t2;
-//   base::get<0>(t2) = 42;
-//   base::get<1>(t2) = 3.14;
-
-template <size_t I, typename T>
-T& get(TupleLeaf<I, T>& leaf) {
-  return leaf.get();
-}
-
-template <size_t I, typename T>
-const T& get(const TupleLeaf<I, T>& leaf) {
-  return leaf.get();
-}
-
-// Tuple types ----------------------------------------------------------------
-//
-// Allows for selection of ValueTuple/RefTuple/ParamTuple without needing the
-// definitions of class types the tuple takes as parameters.
-
-template <typename T>
-struct TupleTypes;
-
-template <typename... Ts>
-struct TupleTypes<Tuple<Ts...>> {
-  using ValueTuple = Tuple<typename TupleTraits<Ts>::ValueType...>;
-  using RefTuple = Tuple<typename TupleTraits<Ts>::RefType...>;
-  using ParamTuple = Tuple<typename TupleTraits<Ts>::ParamType...>;
-};
-
-// Tuple creators -------------------------------------------------------------
-//
-// Helper functions for constructing tuples while inferring the template
-// argument types.
-
-template <typename... Ts>
-inline Tuple<Ts...> MakeTuple(const Ts&... arg) {
-  return Tuple<Ts...>(arg...);
-}
-
-// The following set of helpers make what Boost refers to as "Tiers" - a tuple
-// of references.
-
-template <typename... Ts>
-inline Tuple<Ts&...> MakeRefTuple(Ts&... arg) {
-  return Tuple<Ts&...>(arg...);
-}
-
-// Dispatchers ----------------------------------------------------------------
-//
-// Helper functions that call the given method on an object, with the unpacked
-// tuple arguments.  Notice that they all have the same number of arguments,
-// so you need only write:
-//   DispatchToMethod(object, &Object::method, args);
-// This is very useful for templated dispatchers, since they don't need to know
-// what type |args| is.
-
-// Non-Static Dispatchers with no out params.
-
-template <typename ObjT, typename Method, typename A>
-inline void DispatchToMethod(ObjT* obj, Method method, const A& arg) {
-  (obj->*method)(base::internal::UnwrapTraits<A>::Unwrap(arg));
-}
-
-template <typename ObjT, typename Method, typename... Ts, size_t... Ns>
-inline void DispatchToMethodImpl(ObjT* obj,
-                                 Method method,
-                                 const Tuple<Ts...>& arg,
-                                 IndexSequence<Ns...>) {
-  (obj->*method)(base::internal::UnwrapTraits<Ts>::Unwrap(get<Ns>(arg))...);
-}
-
-template <typename ObjT, typename Method, typename... Ts>
-inline void DispatchToMethod(ObjT* obj,
-                             Method method,
-                             const Tuple<Ts...>& arg) {
-  DispatchToMethodImpl(obj, method, arg, MakeIndexSequence<sizeof...(Ts)>());
-}
-
-// Static Dispatchers with no out params.
-
-template <typename Function, typename A>
-inline void DispatchToMethod(Function function, const A& arg) {
-  (*function)(base::internal::UnwrapTraits<A>::Unwrap(arg));
-}
-
-template <typename Function, typename... Ts, size_t... Ns>
-inline void DispatchToFunctionImpl(Function function,
-                                   const Tuple<Ts...>& arg,
-                                   IndexSequence<Ns...>) {
-  (*function)(base::internal::UnwrapTraits<Ts>::Unwrap(get<Ns>(arg))...);
-}
-
-template <typename Function, typename... Ts>
-inline void DispatchToFunction(Function function, const Tuple<Ts...>& arg) {
-  DispatchToFunctionImpl(function, arg, MakeIndexSequence<sizeof...(Ts)>());
-}
-
-// Dispatchers with out parameters.
-
-template <typename ObjT,
-          typename Method,
-          typename In,
-          typename... OutTs,
-          size_t... OutNs>
-inline void DispatchToMethodImpl(ObjT* obj,
-                                 Method method,
-                                 const In& in,
-                                 Tuple<OutTs...>* out,
-                                 IndexSequence<OutNs...>) {
-  (obj->*method)(base::internal::UnwrapTraits<In>::Unwrap(in),
-                 &get<OutNs>(*out)...);
-}
-
-template <typename ObjT, typename Method, typename In, typename... OutTs>
-inline void DispatchToMethod(ObjT* obj,
-                             Method method,
-                             const In& in,
-                             Tuple<OutTs...>* out) {
-  DispatchToMethodImpl(obj, method, in, out,
-                       MakeIndexSequence<sizeof...(OutTs)>());
-}
-
-template <typename ObjT,
-          typename Method,
-          typename... InTs,
-          typename... OutTs,
-          size_t... InNs,
-          size_t... OutNs>
-inline void DispatchToMethodImpl(ObjT* obj,
-                                 Method method,
-                                 const Tuple<InTs...>& in,
-                                 Tuple<OutTs...>* out,
-                                 IndexSequence<InNs...>,
-                                 IndexSequence<OutNs...>) {
-  (obj->*method)(base::internal::UnwrapTraits<InTs>::Unwrap(get<InNs>(in))...,
-                 &get<OutNs>(*out)...);
-}
-
-template <typename ObjT, typename Method, typename... InTs, typename... OutTs>
-inline void DispatchToMethod(ObjT* obj,
-                             Method method,
-                             const Tuple<InTs...>& in,
-                             Tuple<OutTs...>* out) {
-  DispatchToMethodImpl(obj, method, in, out,
-                       MakeIndexSequence<sizeof...(InTs)>(),
-                       MakeIndexSequence<sizeof...(OutTs)>());
-}
-
-}  // namespace base
-
-#endif  // BASE_TUPLE_H_