---
title: CustomCombineIdentifierConvertible
framework: combine
role: symbol
role_heading: Protocol
path: combine/customcombineidentifierconvertible
---

# CustomCombineIdentifierConvertible

A protocol for uniquely identifying publisher streams.

## Declaration

```swift
protocol CustomCombineIdentifierConvertible
```

## Overview

Overview If you create a custom Subscription or Subscriber type, implement this protocol so that development tools can uniquely identify publisher chains in your app. If your type is a class, Combine provides an implementation of combineIdentifier for you. If your type is a structure, set up the identifier as follows: let combineIdentifier = CombineIdentifier()

## Topics

### Identifying publisher streams

- [combineIdentifier](combine/customcombineidentifierconvertible/combineidentifier.md)

## Relationships

### Inherited By

- [Subscriber](combine/subscriber.md)
- [Subscription](combine/subscription.md)

### Conforming Types

- [AnySubscriber](combine/anysubscriber.md)
- [Subscribers.Assign](combine/subscribers/assign.md)
- [Subscribers.Sink](combine/subscribers/sink.md)

## See Also

### Debugging Identifiers

- [CombineIdentifier](combine/combineidentifier.md)