Remove deprecated Callback methods

[kjbracey]

Description (required)

Deprecated methods in Callback removed.

Summary of change (What the change is for and why)

Removing obsolete forms that were deprecated in Mbed OS 5.1 and 5.4. Reduce code size, speed up compilation slightly.

Documentation (Details of any document updates required)

None.

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Pull request type (required)

[] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[X] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results (required)

[] No Tests required for this change (E.g docs only update)
[X] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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Release Notes (required for feature/major PRs)

Summary of changes

Deprecated methods in Callback removed.

Impact of changes

Some code that was generating deprecation warnings will no longer compile at all.

Migration actions required

• Replace construction using Callback(arg, func) with the reversed Callback(func, arg)
• Replace use of attach with simple assignment, such as callback = func; or callback = { func, arg };

[ciarmcom]

@kjbracey-arm, thank you for your changes.
@ARMmbed/mbed-os-core @ARMmbed/mbed-os-maintainers please review.

[evedon]

The removal of deprecated API is planned for Mbed 6. Are we already taking PRs for that release?

[evedon]

Less code: great !

[0xc0170]

The removal of deprecated API is planned for Mbed 6. Are we already taking PRs for that release?

Soon, once we have 5.15rc1.

[bulislaw]

Could we change the:

Migration actions required
Replace removed calls with equivalents shown in previous deprecation warnings since Mbed OS 5.4.

to point user to the right calls with links to up to date docs?

[kjbracey]

Updated - missed one deprecated freestanding Callback-maker function.

[kjbracey]

point user to the right calls

Done - not sure about the docs link though.

This highlighted that one of the 5.4 deprecations was actually bogus at the time: you couldn't replace attach(func, arg) with = before C++11; it only worked to replace attach(func). But since C++11, you can do cb = { func, arg };.

[kjbracey]

I'll be doing a callback docs review alongside the next PR, which makes more significant changes, including the "trivial mode".

I'm just feeding this one through first cos it's easy and quick to review.

[0xc0170]

CI started

[mbed-ci]

Test run: FAILED

Summary: 3 of 4 test jobs failed
Build number : 1
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_build-ARM
• jenkins-ci/mbed-os-ci_build-IAR
• jenkins-ci/mbed-os-ci_build-GCC_ARM

[0xc0170]

Failures are related, please review

[0xc0170]

CI restarted

[mbed-ci]

Test run: FAILED

Summary: 1 of 11 test jobs failed
Build number : 2
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_greentea-test

[0xc0170]

Failures might be related, please review (I restarted the test to make sure they are there).

[kjbracey]

Don't see anything related in the CI, I think some platform may have been having a glitch on the master I was on. Rebased.

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 3
Build artifacts