dom/canvas/ParamTraits_TiedFields.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef MOZILLA_PARAMTRAITS_TIEDFIELDS_H
   7 #define MOZILLA_PARAMTRAITS_TIEDFIELDS_H
   8
   9 #include "ipc/IPCMessageUtils.h"
  10 #include "mozilla/ipc/IPDLParamTraits.h"
  11 #include "TiedFields.h"
  12
  13 namespace IPC {
  14
  15 template <class T>
  16 struct ParamTraits_TiedFields {
  17   static_assert(mozilla::AssertTiedFieldsAreExhaustive<T>());
  18
  19   static void Write(MessageWriter* const writer, const T& in) {
  20     const auto& fields = mozilla::TiedFields(in);
  21     mozilla::MapTuple(fields, [&](const auto& field) {
  22       WriteParam(writer, field);
  23       return true;  // ignored
  24     });
  25   }
  26
  27   static bool Read(MessageReader* const reader, T* const out) {
  28     const auto& fields = mozilla::TiedFields(*out);
  29     bool ok = true;
  30     mozilla::MapTuple(fields, [&](auto& field) {
  31       if (ok) {
  32         ok &= ReadParam(reader, &field);
  33       }
  34       return true;  // ignored
  35     });
  36     return ok;
  37   }
  38 };
  39
  40 // -
  41
  42 template <class U, size_t N>
  43 struct ParamTraits<mozilla::PaddingField<U, N>> final
  44     : public ParamTraits_TiedFields<mozilla::PaddingField<U, N>> {};
  45
  46 }  // namespace IPC
  47
  48 #endif