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# Publishers.SetFailureType

A publisher that appears to send a specified failure type.

```
struct SetFailureType<Upstream, Failure> where Upstream : Publisher, Failure : Error, Upstream.Failure == Never
```

## Overview

The publisher can’t actually fail with the specified type and finishes normally. Use this publisher type when you need to match the error types for two mismatched publishers.

## Topics

### Creating a set failure type publisher

[`init(upstream:)`](/documentation/Combine/Publishers/SetFailureType/init(upstream:))

Creates a publisher that appears to send a specified failure type.

### Setting failure type

[`setFailureType(to:)`](/documentation/Combine/Publishers/SetFailureType/setFailureType(to:))

Changes the failure type declared by the upstream publisher.

### Declaring supporting types

[`Publishers.SetFailureType.Output`](/documentation/Combine/Publishers/SetFailureType/Output)

The kind of values published by this publisher.

### Inspecting publisher properties

[`upstream`](/documentation/Combine/Publishers/SetFailureType/upstream)

The publisher from which this publisher receives elements.

### Comparing publishers

[`==(_:_:)`](/documentation/Combine/Publishers/SetFailureType/==(_:_:))

Returns a Boolean value that indicates whether two publishers are equivalent.


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