---
title: Key Output Index Masks
framework: coreservices
role: collectionGroup
path: coreservices/carbon_core/unicode_utilities/1390638-key_output_index_masks
---

# Key Output Index Masks

Test the bits in UCKeyOutput values.

## Overview

Overview You can use these masks to test the bits in UCKeyOutput values.

## Topics

### Constants

- [kUCKeyOutputStateIndexMask](coreservices/kuckeyoutputstateindexmask.md)
- [kUCKeyOutputSequenceIndexMask](coreservices/kuckeyoutputsequenceindexmask.md)
- [kUCKeyOutputTestForIndexMask](coreservices/kuckeyoutputtestforindexmask.md)
- [kUCKeyOutputGetIndexMask](coreservices/kuckeyoutputgetindexmask.md)