cc/surfaces/surface_id.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_SURFACES_SURFACE_ID_H_
   6 #define CC_SURFACES_SURFACE_ID_H_
   7
   8 #include "base/compiler_specific.h"
   9 #include "base/containers/hash_tables.h"
  10
  11 namespace cc {
  12
  13 struct SurfaceId {
  14   SurfaceId() : id(0) {}
  15   explicit SurfaceId(uint64_t id) : id(id) {}
  16
  17   bool is_null() const { return id == 0; }
  18
  19   uint64_t id;
  20 };
  21
  22 inline bool operator==(const SurfaceId& a, const SurfaceId& b) {
  23   return a.id == b.id;
  24 }
  25
  26 inline bool operator!=(const SurfaceId& a, const SurfaceId& b) {
  27   return !(a == b);
  28 }
  29
  30 inline bool operator<(const SurfaceId& a, const SurfaceId& b) {
  31   return a.id < b.id;
  32 }
  33
  34 }  // namespace cc
  35
  36 namespace BASE_HASH_NAMESPACE {
  37 #if defined(COMPILER_MSVC)
  38 inline size_t hash_value(const cc::SurfaceId& key) {
  39   return hash_value(key.id);
  40 }
  41 #elif defined(COMPILER_GCC)
  42 template <>
  43 struct hash<cc::SurfaceId> {
  44   size_t operator()(cc::SurfaceId key) const {
  45     return hash<uint64_t>()(key.id);
  46   }
  47 };
  48 #else
  49 #error define a hash function for your compiler
  50 #endif  // COMPILER
  51 }  // namespace BASE_HASH_NAMESPACE
  52
  53 #endif  // CC_SURFACES_SURFACE_ID_H_