Added native return types

[pkruithof]

The ArrayAccess methods have native return types since PHP 7, which can result in deprecation messages like this (when using Symfony's debug classloader):

2022-05-24T14:21:41+00:00 [info] User Deprecated: Method "ArrayAccess::offsetUnset()" might add "void" as a native return type declaration in the future. Do the same in implementation "Dflydev\DotAccessData\Data" now to avoid errors or add an explicit @return annotation to suppress this message.

This PR adds native return types where possible.

[pkruithof]

Because mixed was added after PHP 7.1, it cannot be used as native return type yet.

[colinodell]

I have no problem with these changes, but they do technically break BC (since this class is not final) and would therefore require a major version bump.

[pkruithof]

I could remove the native return types and just add @return docblocks instead?

[pkruithof]

@colinodell what do you propose?

[mutan]

Hello!

The issue is still actual. Annoying notices after phpunit tests.

@simensen @colinodell what about @pkruithof proposal to add @return docblocks? Or any other solution.

  1x: Method "ArrayAccess::offsetExists()" might add "bool" as a native return type declaration in the future. Do the same in implementation "Dflydev\DotAccessData\Data" now to avoid errors or add an explicit @return annotation to suppress this message.

  1x: Method "ArrayAccess::offsetGet()" might add "mixed" as a native return type declaration in the future. Do the same in implementation "Dflydev\DotAccessData\Data" now to avoid errors or add an explicit @return annotation to suppress this message.

  1x: Method "ArrayAccess::offsetSet()" might add "void" as a native return type declaration in the future. Do the same in implementation "Dflydev\DotAccessData\Data" now to avoid errors or add an explicit @return annotation to suppress this message.

  1x: Method "ArrayAccess::offsetUnset()" might add "void" as a native return type declaration in the future. Do the same in implementation "Dflydev\DotAccessData\Data" now to avoid errors or add an explicit @return annotation to suppress this message.```

[madflow]

@pkruithof @colinodell @simensen

Can we kindly do something about these noisy messages in everybodies PHP 8.1 Unit Tests :D

I have created a quick "sister" PR: #45 . This should patch this issue, hopefully without a BC issue.

[colinodell]

#45 seems like a sensible short-term approach as it silences these messages (which users shouldn't have to care about) without breaking BC. And merging #45 wouldn't prevent us from merging this one too (as a new major version) at some point.

[colinodell]

#45 has been merged and released: https://github.com/dflydev/dflydev-dot-access-data/releases/tag/v3.0.2

[pkruithof]

Cool, let me know when you are ready to merge this one, because I suspect I can change the mixed return type too then, since it would be a major version bump and thus probably remove PHP 7.1 support.