Split single boost/gil/concepts.hpp into boost/gil/concepts/*.hpp

[mloskot]

Replaces single, big, complex, of unclear logical structure, difficult to reason about concepts.hpp with collection of structured, clearly named headers.

This PR consists of pure refactoring changes:

• move definitions to new files
• replace Doxygen comments /** and **/with simple///` all the way
• format some extremely long lines and template definitions to readable form respecting80-90 characters long lines
• move some auxiliary internal definitions into namespace detail
• add #include for missing headers
• add #pragma GCC diagnostic ignored "-Wunused-local-typedefs"

This PR does NOT:

• introduce functional changes
• modify content of comments
• modify tests

References

• [rfc] Splitting concepts.hpp thread on boost-gil ML

Tasklist

• Review
• Adjust for comments
• All CI builds and checks have passed

[stefanseefeld]

Thanks for this work ! I find it quite hard to review, as the diff mostly just display added vs. deleted content, rather than providing insight into how things were re-arranged.
I assume this is (mostly) just about moving chunks of code into different locations, then using include directives to re-assemble them as needed ?
In other words, there aren't any semantically relevant changes to the code itself, right ?

[mloskot]

@stefanseefeld Yes, it is difficult to review indeed.

I assume this is (mostly) just about moving chunks of code into different locations,
then using include directives to re-assemble them as needed ?

Correct.

In other words, there aren't any semantically relevant changes to the code itself, right ?

No, no functional changes introduced. Pure refactoring (as labelled :-))

I have just updated description of this PR listing what kind of changes it introduces.

[stefanseefeld]

OK, thanks for confirming that. So I think all looks very good !

[mloskot]

Thanks