Prevent an extra copy of data types that get passed into IPC messages when...

base/tuple.h

 // Copyright (c) 2006-2008 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.
 // There are classes Tuple0 to Tuple6, cooresponding to the number of elements
 // it contains.  The convenient MakeTuple() function takes 0 to 6 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.
@@ skipping 50 matching lines @@
 // Tuple0 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).
 // Tuple1<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.
 
 struct Tuple0 {
   typedef Tuple0 ValueTuple;
   typedef Tuple0 RefTuple;
+  typedef Tuple0 ParamTuple;
 };
 
 template <class A>
 struct Tuple1 {
  public:
   typedef A TypeA;
   typedef Tuple1<typename TupleTraits<A>::ValueType> ValueTuple;
   typedef Tuple1<typename TupleTraits<A>::RefType> RefTuple;
+  typedef Tuple1<typename TupleTraits<A>::ParamType> ParamTuple;
 
   Tuple1() {}
   explicit Tuple1(typename TupleTraits<A>::ParamType a) : a(a) {}
 
   A a;
 };
 
 template <class A, class B>
 struct Tuple2 {
  public:
   typedef A TypeA;
   typedef B TypeB;
   typedef Tuple2<typename TupleTraits<A>::ValueType,
                  typename TupleTraits<B>::ValueType> ValueTuple;
   typedef Tuple2<typename TupleTraits<A>::RefType,
                  typename TupleTraits<B>::RefType> RefTuple;
+  typedef Tuple2<typename TupleTraits<A>::ParamType,
+                 typename TupleTraits<B>::ParamType> ParamTuple;
 
   Tuple2() {}
   Tuple2(typename TupleTraits<A>::ParamType a,
          typename TupleTraits<B>::ParamType b)
       : a(a), b(b) {
   }
 
   A a;
   B b;
 };
 
 template <class A, class B, class C>
 struct Tuple3 {
  public:
   typedef A TypeA;
   typedef B TypeB;
   typedef C TypeC;
   typedef Tuple3<typename TupleTraits<A>::ValueType,
                  typename TupleTraits<B>::ValueType,
                  typename TupleTraits<C>::ValueType> ValueTuple;
   typedef Tuple3<typename TupleTraits<A>::RefType,
                  typename TupleTraits<B>::RefType,
                  typename TupleTraits<C>::RefType> RefTuple;
+  typedef Tuple3<typename TupleTraits<A>::ParamType,
+                 typename TupleTraits<B>::ParamType,
+                 typename TupleTraits<C>::ParamType> ParamTuple;
 
   Tuple3() {}
   Tuple3(typename TupleTraits<A>::ParamType a,
          typename TupleTraits<B>::ParamType b,
          typename TupleTraits<C>::ParamType c)
       : a(a), b(b), c(c){
   }
 
   A a;
   B b;
   C c;
 };
 
 template <class A, class B, class C, class D>
 struct Tuple4 {
  public:
   typedef A TypeA;
   typedef B TypeB;
   typedef C TypeC;
   typedef D TypeD;
   typedef Tuple4<typename TupleTraits<A>::ValueType,
                  typename TupleTraits<B>::ValueType,
                  typename TupleTraits<C>::ValueType,
                  typename TupleTraits<D>::ValueType> ValueTuple;
   typedef Tuple4<typename TupleTraits<A>::RefType,
                  typename TupleTraits<B>::RefType,
                  typename TupleTraits<C>::RefType,
                  typename TupleTraits<D>::RefType> RefTuple;
+  typedef Tuple4<typename TupleTraits<A>::ParamType,
+                 typename TupleTraits<B>::ParamType,
+                 typename TupleTraits<C>::ParamType,
+                 typename TupleTraits<D>::ParamType> ParamTuple;
 
   Tuple4() {}
   Tuple4(typename TupleTraits<A>::ParamType a,
          typename TupleTraits<B>::ParamType b,
          typename TupleTraits<C>::ParamType c,
          typename TupleTraits<D>::ParamType d)
       : a(a), b(b), c(c), d(d) {
   }
 
   A a;
@@ skipping 13 matching lines @@
   typedef Tuple5<typename TupleTraits<A>::ValueType,
     typename TupleTraits<B>::ValueType,
     typename TupleTraits<C>::ValueType,
     typename TupleTraits<D>::ValueType,
     typename TupleTraits<E>::ValueType> ValueTuple;
   typedef Tuple5<typename TupleTraits<A>::RefType,
     typename TupleTraits<B>::RefType,
     typename TupleTraits<C>::RefType,
     typename TupleTraits<D>::RefType,
     typename TupleTraits<E>::RefType> RefTuple;
+  typedef Tuple5<typename TupleTraits<A>::ParamType,
+    typename TupleTraits<B>::ParamType,
+    typename TupleTraits<C>::ParamType,
+    typename TupleTraits<D>::ParamType,
+    typename TupleTraits<E>::ParamType> ParamTuple;
 
   Tuple5() {}
   Tuple5(typename TupleTraits<A>::ParamType a,
     typename TupleTraits<B>::ParamType b,
     typename TupleTraits<C>::ParamType c,
     typename TupleTraits<D>::ParamType d,
     typename TupleTraits<E>::ParamType e)
     : a(a), b(b), c(c), d(d), e(e) {
   }
 
@@ skipping 18 matching lines @@
     typename TupleTraits<C>::ValueType,
     typename TupleTraits<D>::ValueType,
     typename TupleTraits<E>::ValueType,
     typename TupleTraits<F>::ValueType> ValueTuple;
   typedef Tuple6<typename TupleTraits<A>::RefType,
     typename TupleTraits<B>::RefType,
     typename TupleTraits<C>::RefType,
     typename TupleTraits<D>::RefType,
     typename TupleTraits<E>::RefType,
     typename TupleTraits<F>::RefType> RefTuple;
+  typedef Tuple6<typename TupleTraits<A>::ParamType,
+    typename TupleTraits<B>::ParamType,
+    typename TupleTraits<C>::ParamType,
+    typename TupleTraits<D>::ParamType,
+    typename TupleTraits<E>::ParamType,
+    typename TupleTraits<F>::ParamType> ParamTuple;
 
   Tuple6() {}
   Tuple6(typename TupleTraits<A>::ParamType a,
     typename TupleTraits<B>::ParamType b,
     typename TupleTraits<C>::ParamType c,
     typename TupleTraits<D>::ParamType d,
     typename TupleTraits<E>::ParamType e,
     typename TupleTraits<F>::ParamType f)
     : a(a), b(b), c(c), d(d), e(e), f(f) {
   }
@@ skipping 23 matching lines @@
     typename TupleTraits<E>::ValueType,
     typename TupleTraits<F>::ValueType,
     typename TupleTraits<G>::ValueType> ValueTuple;
   typedef Tuple7<typename TupleTraits<A>::RefType,
     typename TupleTraits<B>::RefType,
     typename TupleTraits<C>::RefType,
     typename TupleTraits<D>::RefType,
     typename TupleTraits<E>::RefType,
     typename TupleTraits<F>::RefType,
     typename TupleTraits<G>::RefType> RefTuple;
+  typedef Tuple7<typename TupleTraits<A>::ParamType,
+    typename TupleTraits<B>::ParamType,
+    typename TupleTraits<C>::ParamType,
+    typename TupleTraits<D>::ParamType,
+    typename TupleTraits<E>::ParamType,
+    typename TupleTraits<F>::ParamType,
+    typename TupleTraits<G>::ParamType> ParamTuple;
 
   Tuple7() {}
   Tuple7(typename TupleTraits<A>::ParamType a,
     typename TupleTraits<B>::ParamType b,
     typename TupleTraits<C>::ParamType c,
     typename TupleTraits<D>::ParamType d,
     typename TupleTraits<E>::ParamType e,
     typename TupleTraits<F>::ParamType f,
     typename TupleTraits<G>::ParamType g)
     : a(a), b(b), c(c), d(d), e(e), f(f), g(g) {
@@ skipping 599 matching lines @@
          class InA, class InB, class InC, class InD, class InE, class InF,
          class OutA, class OutB, class OutC, class OutD, class OutE>
 inline void DispatchToMethod(ObjT* obj, Method method,
                              const Tuple6<InA, InB, InC, InD, InE, InF>& in,
                              Tuple5<OutA, OutB, OutC, OutD, OutE>* out) {
   (obj->*method)(in.a, in.b, in.c, in.d, in.e, in.f,
                  &out->a, &out->b, &out->c, &out->d, &out->e);
 }
 
 #endif  // BASE_TUPLE_H__