P0767R1 Deprecating is_pod

[crackedmind]

Description

Fixes #36
Added deprecation warning about using is_pod and is_pod_v in C++20 mode

Checklist

• I understand README.md. I also understand that acceptance of
  community PRs will be delayed until the test and CI systems are online.
• If this is a feature addition, that feature has been voted into the
  C++ Working Draft.
• Identifiers in product code changes are properly _Ugly as per
  https://eel.is/c++draft/lex.name#3.1 .
• The STL builds successfully and all tests have passed (must be manually
  verified by an STL maintainer before CI is online, leave this unchecked for
  initial submission).
• These changes introduce no known ABI breaks (adding members, renaming
  members, adding virtual functions, changing whether a type is an aggregate
  or trivially copyable, etc.).
• These changes were written from scratch using only this repository and
  the C++ Working Draft as a reference (and any other cited standards).
  If they were derived from a project that's already listed in NOTICE.txt,
  that's fine, but please mention it. If they were derived from any other
  project (including Boost and libc++, which are not yet listed in
  NOTICE.txt), you must mention it here, so we can determine whether the
  license is compatible and what else needs to be done.

[CaseyCarter]

/azp run

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Azure Pipelines successfully started running 1 pipeline(s).

[CaseyCarter]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[CaseyCarter]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[StephanTLavavej]

I'm preparing a Microsoft-internal PR for this with associated test changes.

[StephanTLavavej]

For future reference: Like is_literal_type and is_literal_type_v, this is currently affected by VSO-437892 "C1XX emits a generic warning C4996 "was declared deprecated" for variable templates declared with [[deprecated("MESSAGE")]]" and VSO-480568 "C1XX should warn about usage of deprecated type traits even when they inherit from non-deprecated classes".

[crackedmind]

Yeah, i found VSO-480568 while testing this feature and created issue

[CaseyCarter]

Yeah, i found VSO-480568 while testing this feature and created issue

Thanks for bringing the issue to our attention: I've internally linked up VSO-480568 with DevCom-782069.

[StephanTLavavej]

Status update: I've sent out that Microsoft-internal PR with tests, so I should be able to merge this tomorrow.