chromium/media/base/media_log_type_enforcement.h

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_MEDIA_LOG_TYPE_ENFORCEMENT_H_
#define MEDIA_BASE_MEDIA_LOG_TYPE_ENFORCEMENT_H_

#include "media/base/media_serializers.h"

namespace media {

namespace internal {
enum class UnmatchableType { … };
}  // namespace internal

// Forward declare the enums.
enum class MediaLogProperty;
enum class MediaLogEvent;

// Allow only specific types for an individual property.
template <MediaLogProperty PROP, typename T>
struct MediaLogPropertyTypeSupport { … };

// Allow only specific types for an individual event.
// However unlike Property, T is not required, so we default it to some
// unmatchable type that will never be passed as an argument accidentally.
template <MediaLogEvent EVENT, typename T = internal::UnmatchableType>
struct MediaLogEventTypeSupport { … };

// Lets us define the supported type in a single line in media_log_properties.h.
#define MEDIA_LOG_PROPERTY_SUPPORTS_TYPE(PROPERTY, TYPE) …

#define MEDIA_LOG_EVENT_NAMED_DATA(EVENT, TYPE, DISPLAY) …

#define MEDIA_LOG_EVENT_NAMED_DATA_OP(EVENT, TYPE, DISPLAY, OP) …

// Specifically do not create the Convert or DisplayName methods
#define MEDIA_LOG_EVENT_TYPELESS(EVENT) …

}  // namespace media

#endif  // MEDIA_BASE_MEDIA_LOG_TYPE_ENFORCEMENT_H_