samples: matter: Allow using enums as keys in the finite map

[ArekBalysNordic]

If the T1 type was an enum type, then the kInvalidKey gets 0 value instead of type::max().
To fix it, conditionally get the underlying type of T1 if it is an enum, and return T1 if not.

[Copilot]

Pull Request Overview

This PR fixes an issue where enum types used as keys in FiniteMap would incorrectly get kInvalidKey set to 0 instead of the maximum value of the enum's underlying type. The fix introduces a KeyTypeHelper template struct to conditionally extract the underlying type for enums while preserving the original type for non-enum types.

• Adds KeyTypeHelper template struct to handle type extraction for both enum and non-enum key types
• Updates kInvalidKey initialization to use the underlying type's maximum value for enums

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[NordicBuilder]

CI Information

^{To view the history of this post, click the 'edited' button above}
Build number: 1

Inputs:

Sources:

sdk-nrf: PR head: 9a3bb49ceb8504083f7c607908ca8047a85089ab

more details

sdk-nrf:

PR head: 9a3bb49ceb8504083f7c607908ca8047a85089ab
merge base: 35246387d4fdc7e84615716a068a57afca940ce2
target head (main): ad7d9b915b4d543e00b23c7b9be6a20dad9c63fd
Diff

Github labels

Enabled	Name	Description
	ci-disabled	Disable the ci execution
	ci-all-test	Run all of ci, no test spec filtering will be done
	ci-force-downstream	Force execution of downstream even if twister fails
	ci-run-twister	Force run twister
	ci-run-zephyr-twister	Force run zephyr twister

List of changed files detected by CI (1)

samples
│  ├── matter
│  │  ├── common
│  │  │  ├── src
│  │  │  │  ├── util
│  │  │  │  │  │ finite_map.h

Outputs:

Toolchain

Version: df3cc9d822
Build docker image: docker-dtr.nordicsemi.no/sw-production/ncs-build:df3cc9d822_e595b21c39

Test Spec & Results: ✅ Success; ❌ Failure; 🟠 Queued; 🟡 Progress; ◻️ Skipped; ⚠️ Quarantine

• ◻️ Toolchain - Skipped: existing toolchain is used
• ✅ Build twister
  • sdk-nrf test count: 104
• ✅ Integration tests
  • ✅ test-fw-nrfconnect-chip

Disabled integration tests

• • test-fw-nrfconnect-nrf_lrcs_positioning
  • desktop52_verification
  • test_ble_nrf_config
  • test-fw-nrfconnect-apps
  • test-fw-nrfconnect-ble_mesh
  • test-fw-nrfconnect-ble_samples
  • test-fw-nrfconnect-fem
  • test-fw-nrfconnect-nfc
  • test-fw-nrfconnect-nrf-iot_libmodem-nrf
  • test-fw-nrfconnect-nrf-iot_lwm2m
  • test-fw-nrfconnect-nrf-iot_samples
  • test-fw-nrfconnect-nrf-iot_thingy91
  • test-fw-nrfconnect-nrf-iot_zephyr_lwm2m
  • test-fw-nrfconnect-nrf_crypto
  • test-fw-nrfconnect-ps-main
  • test-fw-nrfconnect-rpc
  • test-fw-nrfconnect-rs
  • test-fw-nrfconnect-tfm
  • test-fw-nrfconnect-thread-main
  • test-low-level
  • test-sdk-audio
  • test-sdk-dfu
  • test-sdk-find-my
  • test-sdk-mcuboot
  • test-sdk-wifi
  • test-secdom-samples-public

Note: This message is automatically posted and updated by the CI

[NordicBuilder]

Memory footprint analysis revealed the following potential issues

sample.matter.template.debug[nrf5340dk/nrf5340/cpuapp]: RAM size increased by 2048[B] in comparison to the main[3524638] branch. - link (cc: @kkasperczyk-no @ArekBalysNordic @markaj-nordic)
sample.matter.template.release[nrf5340dk/nrf5340/cpuapp]: RAM size increased by 2048[B] in comparison to the main[3524638] branch. - link (cc: @kkasperczyk-no @ArekBalysNordic @markaj-nordic)
sample.matter.template.debug[nrf52840dk/nrf52840]: RAM size increased by 2048[B] in comparison to the main[3524638] branch. - link (cc: @kkasperczyk-no @ArekBalysNordic @markaj-nordic)
sample.matter.template.release[nrf52840dk/nrf52840]: RAM size increased by 2048[B] in comparison to the main[3524638] branch. - link (cc: @kkasperczyk-no @ArekBalysNordic @markaj-nordic)

Note: This message is automatically posted and updated by the CI (latest/sdk-nrf/PR-25477/1)