Fixing std::optional handling being redundant in Boost version > 1.80

[talregev]

In macos vm, recently we get a newer version of boost (1.84).
They already implemented in the new version the function that gtsam implemented.
So I am not sure the correct version of boost that it begin to happen, so I put version 1.80.
We can tune the version later (when we have another issue similar to that in different boost version).

@varunagrawal @ProfFan
Thank you for your time and effort for review this PR.

[varunagrawal]

We're looking to remove boost altogether so we probably don't need this PR

[varunagrawal]

Also the PR comment doesn't mention what the issue is or what it fixes.

[talregev]

Also the PR comment doesn't mention what the issue is or what it fixes.

I can fix the comment. That is for code review.

I hope you will fix the boost issue soon!.

[ProfFan]

So this is for std：：optional？

[ProfFan]

@talregev Could you edit the title to say the exact issue this fixes? Thank you very much!

[ProfFan]

Also is this change in boost happening in 1.80 only? Could you link the Boost change note as well?

[talregev]

I don't mind changing the title. I added CI there. You can write me the title that it will be more informative for you.

@ProfFan Thank you for opening this PR again.

[talregev]

Also is this change in boost happening in 1.80 only? Could you link the Boost change note as well?

As I stated in the first msg, I am not sure what version this was happening.
My guess is it started at 1.8 and we can tune this later.

[ProfFan]

Also is this change in boost happening in 1.80 only? Could you link the Boost change note as well?

As I stated in the first msg, I am not sure what version this was happening.
My guess is it started at 1.8 and we can tune this later.

Please check the Boost release notes. Title could be 'Fixing std::optional handling being redundant in Boost version > 1.xx'

But be sure to check the version number, we could accidentally break others' code!

[talregev]

Also is this change in boost happening in 1.80 only? Could you link the Boost change note as well?

As I stated in the first msg, I am not sure what version this was happening.
My guess is it started at 1.8 and we can tune this later.

Please check the Boost release notes. Title could be 'Fixing std::optional handling being redundant in Boost version > 1.xx'

But be sure to check the version number, we could accidentally break others' code!

Can you help me and search also?
I think it found in 1.80
https://www.boost.org/users/history/version_1_80_0.html

Optional:
Added specializations for std::hash<boost::optional>. This is a breaking change for programs that define such specializations themselves. For more details see specs.

[ProfFan]

Good, please change the title and add a comment above the code that says // See CHANGELOG: <link>

[talregev]

Good, please change the title and add a comment above the code that says // See CHANGELOG: <link>

Can you write the exact title you want?

[ProfFan]

Suggested change

	// Only for old boost
	// NOTE: Added in Boost 1.80
	// See Boost CHANGELOG: https://www.boost.org/users/history/version_1_80_0.html

[varunagrawal]

I don't think this is the cause of the issue. I looked at the commit history of boost/serialization/optional.hpp and this commit boostorg/serialization@ff0a5f9 was quite enlightening. Note that there have been only 2 changes in the file since 2020.

Essentially, the authors fixed the inclusion of std::optional primarily for upgrading to C++17. There have been related updates to add save, load, etc, to accommodate this. The easier fix is to check for the C++ version and conditionally compile based on that. I have included the fix in #1723.

[varunagrawal]

I looked into it more closely, and the real issue is this PR: https://github.com/boostorg/serialization/pull/163/files

It got merged on 09/02/2023 and std_optional_serialization.hpp is based on the changes in that PR. Thus we are seeing duplicates just for 1.84.0.

[ProfFan]

Since I got no response from @talregev I'll just merge this PR so the issue gets fixed fast and we don't waste any more cycles on this. @varunagrawal I believe the actual commit is boostorg/serialization@61a2b12, the PR you linked was reverted. But you are right, correct boost version is 1.84 due to the addition of std::optional serialization. Could you rebase on develop and make the necessary corrections? Thank you very much!