expanded_value_base.h | Explore in Territory

// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CAST_STREAMING_IMPL_EXPANDED_VALUE_BASE_H_
#define CAST_STREAMING_IMPL_EXPANDED_VALUE_BASE_H_

#include <stdint.h>

#include <limits>

#include "util/osp_logging.h"

namespace openscreen::cast {

// Abstract base template class for common "sequence value" data types such as
// RtpTimeTicks, FrameId, or PacketId which generally increment/decrement in
// predictable amounts as media is streamed, and which often need to be reliably
// truncated and re-expanded for over-the-wire transmission.
//
// FullWidthInteger should be a signed integer POD type that is of sufficiently
// high width (in bits) such that it is never expected to under/overflow during
// the longest reasonable length of continuous system operation.  Subclass is
// the class inheriting the common functionality provided in this template, and
// is used to provide operator overloads.  The Subclass must friend this class
// to enable these operator overloads.
//
// Please see RtpTimeTicks and unit test code for examples of how to define
// Subclasses and add features specific to their concrete data type, and how to
// use data types derived from ExpandedValueBase.  For example, a RtpTimeTicks
// adds math operators consisting of the meaningful and valid set of operations
// allowed for doing "time math."  On the other hand, FrameId only adds math
// operators for incrementing/decrementing since multiplication and division are
// meaningless.
template <typename FullWidthInteger, class Subclass>
class ExpandedValueBase { … };

}  // namespace openscreen::cast

#endif  // CAST_STREAMING_IMPL_EXPANDED_VALUE_BASE_H_
chromium/third_party/openscreen/src/cast/streaming/impl/expanded_value_base.h
