Add GCC and MSVC settings to ensure C++ standard conformance

[doomlaur]

To ensure C++ standard conformance in the future, this PR:

• adds -Wpedantic for GCC, and -pedantic-errors if XLNT_ALL_WARNINGS_AS_ERRORS is set
• adds /permissive- for MSVC 2017 and newer
• note: for Clang, we already used -Weverything, which already sets -Wpedantic

Depends on #131 to fix compilation under MSVC 2017 (see discussion below).

[m7913d]

Coverage report is available at: full | review summary

[coveralls]

Pull Request Test Coverage Report for Build ffc61b29-c678-4be2-9cce-415c1e565ae2

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 82.718%

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Totals
Change from base Build fcbaa237-6534-4795-9135-85f999fd1fde:	0.0%
Covered Lines:	11837
Relevant Lines:	14310

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💛 - Coveralls

[m7913d]

Coverage report is available at: full | review summary

[m7913d]

Coverage report is available at: full | review summary

[m7913d]

Coverage report is available at: full | review summary

[m7913d]

Coverage report is available at: full | review summary

[m7913d]

Coverage report is available at: full | review summary

[doomlaur]

I think the compilation error with MSVC 2017 is due to a bug in MSVC 2017 triggered by fmt. Before writing more information, I'll update fmt very quickly to test my theory, then remove the update from this PR and add its own PR for it.

[m7913d]

Coverage report is available at: full | review summary

[doomlaur]

Alright, it seems that MSVC 2017 with /permissive- breaks due to issue fmtlib/fmt#4412 and has been fixed by PR fmtlib/fmt#4413, which is available since fmt 11.2.0. We were previously using a commit from the master branch from fmt between 11.1.2 and 11.1.3. I will send another PR for updating fmt.

While I would have liked to update our dependencies shortly before releasing XLNT 1.7.0, I will make an exception here (and we can also update fmt twice too, if we think it's worth it). I will update the other dependencies shortly before XLNT 1.7.0.

[m7913d]

Coverage report is available at: full | review summary

[m7913d]

I'm already approving, so you can merge the PR once the failed test is fixed (by the other PR).

[m7913d]

Coverage report is available at: full | review summary