chromium/base/token.h

// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TOKEN_H_
#define BASE_TOKEN_H_

#include <stdint.h>

#include <array>
#include <compare>
#include <optional>
#include <string>
#include <string_view>

#include "base/base_export.h"
#include "base/containers/span.h"

namespace base {

// A Token is a randomly chosen 128-bit integer. This class supports generation
// from a cryptographically strong random source, or constexpr construction over
// fixed values (e.g. to store a pre-generated constant value). Tokens are
// similar in spirit and purpose to UUIDs, without many of the constraints and
// expectations (such as byte layout and string representation) clasically
// associated with UUIDs.
class BASE_EXPORT Token { … };

// For use in std::unordered_map.
struct BASE_EXPORT TokenHash { … };

class Pickle;
class PickleIterator;

// For serializing and deserializing Token values.
BASE_EXPORT void WriteTokenToPickle(Pickle* pickle, const Token& token);
BASE_EXPORT std::optional<Token> ReadTokenFromPickle(
    PickleIterator* pickle_iterator);

}  // namespace base

#endif  // BASE_TOKEN_H_