[PROPOSAL] useconstexpr instead of inline constexpr for functions

[vil02]

Description

While browsing though the C++ code I have noticed that many functions have inline constexpr specifiers. According to C++ reference for constexpr: A constexpr specifier used in a function or static data member(since C++17) declaration implies inline.

Build and tests pass on my end.

Checklist

• A description of the changes in this PR is mentioned above.
• All the new and existing tests pass.
• The code follows the code style and conventions of the project.
• No plagiarized, duplicated, or repetitive code that has been directly copied from another source.
• I have read the whole Contributing guidelines of the project and its resources/related pages.

Screenshots (if any)

Note to reviewers

Make all inline constexpr functions constexpr.

[mertcandav]

Hi.

You are right, but Jule also supports C++14 standard. This changes still implements inline for C++14 standard?
We can create preprocessor define for C++14 standard. If C++14 standard is used, this define represents inline, if not, represents nothing. So we can have inline for C++14 standard compilations.

Also, I think we can continue to use inline constexpr instead of constexpr if there is no problem (such as compiler errors or etc.) about it.

Thanks for your effort.

[vil02]

This has nothing to do with the version of C++: constexpr function is inline in C++11, C++14, C++17 etc. (constexpr was introduced in C++11).

[mertcandav]

Right but reference says: constexpr implies inline for functions since C++17.
So constexpr not implies inline in C++14, by reference.

[vil02]

No.

Please have a look at the cpp reference. There are two statements here:

• A constexpr specifier used in a function declaration implies inline.
• (since C++17) A constexpr specifier used in a static data member declaration implies inline.

[mertcandav]

Oh, yes. Sorry.
I just missed separated part for static members.

I'll merge your PR.
Thanks for your contribution.

[vil02]

No worries. The formatting there is tricky.

Thanks!